diff --git a/app/controllers/health/airbrake.controller.js b/app/controllers/health/airbrake.controller.js
index 6ce7bba67b..b4c9d3e08e 100644
--- a/app/controllers/health/airbrake.controller.js
+++ b/app/controllers/health/airbrake.controller.js
@@ -5,22 +5,22 @@
  * @module AirbrakeController
  */
 
-class AirbrakeController {
-  static async index (request, _h) {
-    // First section tests connecting to Airbrake through a manual notification
-    request.server.app.airbrake.notify({
-      message: 'Airbrake manual health check',
-      error: new Error('Airbrake manual health check error'),
-      session: {
-        req: {
-          id: request.info.id
-        }
+async function index (request, _h) {
+  // First section tests connecting to Airbrake through a manual notification
+  request.server.app.airbrake.notify({
+    message: 'Airbrake manual health check',
+    error: new Error('Airbrake manual health check error'),
+    session: {
+      req: {
+        id: request.info.id
       }
-    })
+    }
+  })
 
-    // Second section throws an error and checks that we automatically capture it and then connect to Airbrake
-    throw new Error('Airbrake automatic health check error')
-  }
+  // Second section throws an error and checks that we automatically capture it and then connect to Airbrake
+  throw new Error('Airbrake automatic health check error')
 }
 
-module.exports = AirbrakeController
+module.exports = {
+  index
+}
diff --git a/app/controllers/health/database.controller.js b/app/controllers/health/database.controller.js
index 68d986a3d7..dc59b2c61f 100644
--- a/app/controllers/health/database.controller.js
+++ b/app/controllers/health/database.controller.js
@@ -7,12 +7,12 @@
 
 const DatabaseHealthCheckService = require('../../services/database-health-check.service.js')
 
-class DatabaseController {
-  static async index (_request, h) {
-    const result = await DatabaseHealthCheckService.go()
+async function index (_request, h) {
+  const result = await DatabaseHealthCheckService.go()
 
-    return h.response(result).code(200)
-  }
+  return h.response(result).code(200)
 }
 
-module.exports = DatabaseController
+module.exports = {
+  index
+}
diff --git a/app/controllers/root.controller.js b/app/controllers/root.controller.js
index 24b7e6a234..71730f966c 100644
--- a/app/controllers/root.controller.js
+++ b/app/controllers/root.controller.js
@@ -7,27 +7,20 @@
 
 const ServiceStatusService = require('../services/service-status.service.js')
 
-class RootController {
-  static async index (_request, _h) {
-    return { status: 'alive' }
-  }
-
-  static helloWorld (_request, h) {
-    return h.view('home.njk', {
-      title: 'Hello',
-      message: 'World',
-      pageTitle: 'Hello World!'
-    })
-  }
+async function index (_request, _h) {
+  return { status: 'alive' }
+}
 
-  static async serviceStatus (_request, h) {
-    const pageData = await ServiceStatusService.go()
+async function serviceStatus (_request, h) {
+  const pageData = await ServiceStatusService.go()
 
-    return h.view('service_status.njk', {
-      pageTitle: 'Service Status',
-      ...pageData
-    })
-  }
+  return h.view('service_status.njk', {
+    pageTitle: 'Service Status',
+    ...pageData
+  })
 }
 
-module.exports = RootController
+module.exports = {
+  index,
+  serviceStatus
+}
diff --git a/app/controllers/test/supplementary.controller.js b/app/controllers/test/supplementary.controller.js
index 90084db350..09757cd84b 100644
--- a/app/controllers/test/supplementary.controller.js
+++ b/app/controllers/test/supplementary.controller.js
@@ -7,12 +7,12 @@
 
 const SupplementaryService = require('../../services/supplementary-billing/supplementary.service.js')
 
-class SupplementaryController {
-  static async index (request, h) {
-    const result = await SupplementaryService.go(request.query.region)
+async function index (request, h) {
+  const result = await SupplementaryService.go(request.query.region)
 
-    return h.response(result).code(200)
-  }
+  return h.response(result).code(200)
 }
 
-module.exports = SupplementaryController
+module.exports = {
+  index
+}
diff --git a/app/presenters/supplementary.presenter.js b/app/presenters/supplementary.presenter.js
index e318099a4e..1c6d45bc06 100644
--- a/app/presenters/supplementary.presenter.js
+++ b/app/presenters/supplementary.presenter.js
@@ -5,39 +5,31 @@
  * @module SupplementaryPresenter
  */
 
-class SupplementaryPresenter {
-  constructor (data) {
-    this._data = data
-  }
-
-  go () {
-    return this._presentation(this._data)
-  }
-
-  _presentation (data) {
-    const licences = data.licences.map((licence) => {
-      return {
-        licenceId: licence.licenceId,
-        licenceRef: licence.licenceRef
-      }
-    })
-    const chargeVersions = data.chargeVersions.map((chargeVersion) => {
-      return {
-        chargeVersionId: chargeVersion.chargeVersionId,
-        licenceRef: chargeVersion.licenceRef,
-        licenceId: chargeVersion.licenceId,
-        scheme: chargeVersion.scheme,
-        startDate: chargeVersion.startDate,
-        endDate: chargeVersion.endDate
-      }
-    })
-
+function go (data) {
+  const licences = data.licences.map((licence) => {
     return {
-      billingPeriods: data.billingPeriods,
-      licences,
-      chargeVersions
+      licenceId: licence.licenceId,
+      licenceRef: licence.licenceRef
     }
+  })
+  const chargeVersions = data.chargeVersions.map((chargeVersion) => {
+    return {
+      chargeVersionId: chargeVersion.chargeVersionId,
+      licenceRef: chargeVersion.licenceRef,
+      licenceId: chargeVersion.licenceId,
+      scheme: chargeVersion.scheme,
+      startDate: chargeVersion.startDate,
+      endDate: chargeVersion.endDate
+    }
+  })
+
+  return {
+    billingPeriods: data.billingPeriods,
+    licences,
+    chargeVersions
   }
 }
 
-module.exports = SupplementaryPresenter
+module.exports = {
+  go
+}
diff --git a/app/routes/root.routes.js b/app/routes/root.routes.js
index 5296f054ef..f42a50f973 100644
--- a/app/routes/root.routes.js
+++ b/app/routes/root.routes.js
@@ -19,14 +19,6 @@ const routes = [
       auth: false
     }
   },
-  {
-    method: 'GET',
-    path: '/hello-world',
-    handler: RootController.helloWorld,
-    options: {
-      auth: false
-    }
-  },
   {
     method: 'GET',
     path: '/service-status',
diff --git a/app/services/database-health-check.service.js b/app/services/database-health-check.service.js
index af98ba6be3..c9559702e4 100644
--- a/app/services/database-health-check.service.js
+++ b/app/services/database-health-check.service.js
@@ -8,20 +8,22 @@
 const { db } = require('../../db/db.js')
 
 /**
- * Generates an array of stats for each table in the database when `go()` is called
+ * Generates an array of stats for each table in the database
  *
  * This is a dump of running `SELECT * FROM pg_stat_user_tables` for the database. It's part of the database
  * healthcheck and we use it for 2 reasons
  *
  * - confirm we can connect
  * - get some basic stats, for example number of records, for each table without needing to connect to the db
+ *
+ * @returns an array of stats for each table found in the db
 */
-class DatabaseHealthCheckService {
-  static async go () {
-    const stats = db.select().table('pg_stat_user_tables')
+async function go () {
+  const stats = db.select().table('pg_stat_user_tables')
 
-    return stats
-  }
+  return stats
 }
 
-module.exports = DatabaseHealthCheckService
+module.exports = {
+  go
+}
diff --git a/app/services/service-status.service.js b/app/services/service-status.service.js
index 0f7f60b86b..8e51cc310c 100644
--- a/app/services/service-status.service.js
+++ b/app/services/service-status.service.js
@@ -19,140 +19,140 @@ const servicesConfig = require('../../config/services.config.js')
  * Each data set is returned in the format needed to populate the gov.uk table elements ie. an array containing one
  * array per row, where each row array contains multiple `{ text: '...' }` elements, one for each cell in the row.
 */
-class ServiceStatusService {
-  static async go () {
-    const virusScannerData = await this._getVirusScannerData()
-    const redisConnectivityData = await this._getRedisConnectivityData()
-
-    const addressFacadeData = await this._getAddressFacadeData()
-    const chargingModuleData = await this._getChargingModuleData()
-    const appData = await this._getAppData()
-
-    return {
-      virusScannerData,
-      redisConnectivityData,
-      addressFacadeData,
-      chargingModuleData,
-      appData
-    }
+async function go () {
+  const virusScannerData = await _getVirusScannerData()
+  const redisConnectivityData = await _getRedisConnectivityData()
+
+  const addressFacadeData = await _getAddressFacadeData()
+  const chargingModuleData = await _getChargingModuleData()
+  const appData = await _getAppData()
+
+  return {
+    virusScannerData,
+    redisConnectivityData,
+    addressFacadeData,
+    chargingModuleData,
+    appData
   }
+}
 
-  /**
-   * Receives an array and returns it in the format required by the nunjucks template in the view.
-   */
-  static _mapArrayToTextCells (rows) {
-    return rows.map(row => {
-      return row.map(cell => {
-        return { text: cell }
-      })
+/**
+ * Receives an array and returns it in the format required by the nunjucks template in the view.
+ */
+function _mapArrayToTextCells (rows) {
+  return rows.map(row => {
+    return row.map(cell => {
+      return { text: cell }
     })
-  }
-
-  static async _getVirusScannerData () {
-    try {
-      const { stdout, stderr } = await exec('clamdscan --version')
-      return stderr ? `ERROR: ${stderr}` : stdout
-    } catch (error) {
-      return `ERROR: ${error.message}`
-    }
-  }
+  })
+}
 
-  static async _getRedisConnectivityData () {
-    try {
-      const { stdout, stderr } = await exec('redis-server --version')
-      return stderr ? `ERROR: ${stderr}` : stdout
-    } catch (error) {
-      return `ERROR: ${error.message}`
-    }
+async function _getVirusScannerData () {
+  try {
+    const { stdout, stderr } = await exec('clamdscan --version')
+    return stderr ? `ERROR: ${stderr}` : stdout
+  } catch (error) {
+    return `ERROR: ${error.message}`
   }
+}
 
-  static async _getAddressFacadeData () {
-    const statusUrl = new URL('/address-service/hola', servicesConfig.addressFacade.url)
-    const result = await this._requestData(statusUrl)
-
-    return result.succeeded ? result.response.body : result.response
+async function _getRedisConnectivityData () {
+  try {
+    const { stdout, stderr } = await exec('redis-server --version')
+    return stderr ? `ERROR: ${stderr}` : stdout
+  } catch (error) {
+    return `ERROR: ${error.message}`
   }
+}
 
-  static async _getChargingModuleData () {
-    const statusUrl = new URL('/status', servicesConfig.chargingModule.url)
-    const result = await this._requestData(statusUrl)
+async function _getAddressFacadeData () {
+  const statusUrl = new URL('/address-service/hola', servicesConfig.addressFacade.url)
+  const result = await _requestData(statusUrl)
 
-    return result.succeeded ? result.response.headers['x-cma-docker-tag'] : result.response
-  }
+  return result.succeeded ? result.response.body : result.response
+}
 
-  static async _requestData (url) {
-    // As of v12, the got dependency no longer supports CJS modules. This causes us a problem as we are locked into
-    // using these for the time being. Some workarounds are provided here: https://github.com/sindresorhus/got/issues/1789
-    // We have gone the route of using await import('got'). We cannot do this at the top level as Node doesn't support
-    // top level in CJS so we do it here instead.
-    const { got } = await import('got')
-    const result = {
-      succeeded: true,
-      response: null
-    }
+async function _getChargingModuleData () {
+  const statusUrl = new URL('/status', servicesConfig.chargingModule.url)
+  const result = await _requestData(statusUrl)
 
-    try {
-      result.response = await got.get(url, {
-        retry: {
-          // We ensure that the only network errors Got retries are timeout errors
-          errorCodes: ['ETIMEDOUT'],
-          // We set statusCodes as an empty array to ensure that 4xx, 5xx etc. errors are not retried
-          statusCodes: []
-        }
-      })
-    } catch (error) {
-      const statusCode = error.response ? error.response.statusCode : 'N/A'
-      result.response = `ERROR: ${statusCode} - ${error.name} - ${error.message}`
-      result.succeeded = false
-    }
+  return result.succeeded ? result.response.headers['x-cma-docker-tag'] : result.response
+}
 
-    return result
+async function _requestData (url) {
+  // As of v12, the got dependency no longer supports CJS modules. This causes us a problem as we are locked into
+  // using these for the time being. Some workarounds are provided here: https://github.com/sindresorhus/got/issues/1789
+  // We have gone the route of using await import('got'). We cannot do this at the top level as Node doesn't support
+  // top level in CJS so we do it here instead.
+  const { got } = await import('got')
+  const result = {
+    succeeded: true,
+    response: null
   }
 
-  static _getImportJobsData () {
-    return this._mapArrayToTextCells([
-      [
-        'Cell 1.1',
-        'Cell 1.2'
-      ],
-      [
-        'Cell 2.1',
-        'Cell 2.2'
-      ]
-    ])
+  try {
+    result.response = await got.get(url, {
+      retry: {
+        // We ensure that the only network errors Got retries are timeout errors
+        errorCodes: ['ETIMEDOUT'],
+        // We set statusCodes as an empty array to ensure that 4xx, 5xx etc. errors are not retried
+        statusCodes: []
+      }
+    })
+  } catch (error) {
+    const statusCode = error.response ? error.response.statusCode : 'N/A'
+    result.response = `ERROR: ${statusCode} - ${error.name} - ${error.message}`
+    result.succeeded = false
   }
 
-  static async _getAppData () {
-    const healthInfoPath = '/health/info'
-    const services = [
-      { name: 'Service - foreground', url: new URL(healthInfoPath, servicesConfig.serviceForeground.url) },
-      { name: 'Service - background', url: new URL(healthInfoPath, servicesConfig.serviceBackground.url) },
-      { name: 'Reporting', url: new URL(healthInfoPath, servicesConfig.reporting.url) },
-      { name: 'Import', url: new URL(healthInfoPath, servicesConfig.import.url) },
-      { name: 'Tactical CRM', url: new URL(healthInfoPath, servicesConfig.tacticalCrm.url) },
-      { name: 'External UI', url: new URL(healthInfoPath, servicesConfig.externalUi.url) },
-      { name: 'Internal UI', url: new URL(healthInfoPath, servicesConfig.internalUi.url) },
-      { name: 'Tactical IDM', url: new URL(healthInfoPath, servicesConfig.tacticalIdm.url) },
-      { name: 'Permit repository', url: new URL(healthInfoPath, servicesConfig.permitRepository.url) },
-      { name: 'Returns', url: new URL(healthInfoPath, servicesConfig.returns.url) }
+  return result
+}
+
+function _getImportJobsData () {
+  return _mapArrayToTextCells([
+    [
+      'Cell 1.1',
+      'Cell 1.2'
+    ],
+    [
+      'Cell 2.1',
+      'Cell 2.2'
     ]
+  ])
+}
 
-    for (const service of services) {
-      const result = await this._requestData(service.url)
-
-      if (result.succeeded) {
-        const data = JSON.parse(result.response.body)
-        service.version = data.version
-        service.commit = data.commit
-        service.jobs = service.name === 'Import' ? this._getImportJobsData() : []
-      } else {
-        service.version = result.response
-        service.commit = ''
-      }
+async function _getAppData () {
+  const healthInfoPath = '/health/info'
+  const services = [
+    { name: 'Service - foreground', url: new URL(healthInfoPath, servicesConfig.serviceForeground.url) },
+    { name: 'Service - background', url: new URL(healthInfoPath, servicesConfig.serviceBackground.url) },
+    { name: 'Reporting', url: new URL(healthInfoPath, servicesConfig.reporting.url) },
+    { name: 'Import', url: new URL(healthInfoPath, servicesConfig.import.url) },
+    { name: 'Tactical CRM', url: new URL(healthInfoPath, servicesConfig.tacticalCrm.url) },
+    { name: 'External UI', url: new URL(healthInfoPath, servicesConfig.externalUi.url) },
+    { name: 'Internal UI', url: new URL(healthInfoPath, servicesConfig.internalUi.url) },
+    { name: 'Tactical IDM', url: new URL(healthInfoPath, servicesConfig.tacticalIdm.url) },
+    { name: 'Permit repository', url: new URL(healthInfoPath, servicesConfig.permitRepository.url) },
+    { name: 'Returns', url: new URL(healthInfoPath, servicesConfig.returns.url) }
+  ]
+
+  for (const service of services) {
+    const result = await _requestData(service.url)
+
+    if (result.succeeded) {
+      const data = JSON.parse(result.response.body)
+      service.version = data.version
+      service.commit = data.commit
+      service.jobs = service.name === 'Import' ? _getImportJobsData() : []
+    } else {
+      service.version = result.response
+      service.commit = ''
     }
-
-    return services
   }
+
+  return services
 }
 
-module.exports = ServiceStatusService
+module.exports = {
+  go
+}
diff --git a/app/services/supplementary-billing/billing-period.service.js b/app/services/supplementary-billing/billing-period.service.js
index 6fc8f20662..f668c7ef7b 100644
--- a/app/services/supplementary-billing/billing-period.service.js
+++ b/app/services/supplementary-billing/billing-period.service.js
@@ -5,55 +5,51 @@
  * @module BillingPeriodService
  */
 
-class BillingPeriodService {
-  /**
-   * Returns the billing periods needed when generating a supplementary bill run
-   *
-   * **IMPORANT!** This service currently only handles SROC billing periods and only the 'current year'
-   *
-   * Using the current date at the time the service is called, it calculates the billing periods to use. We permit
-   * changes to charge versions to be retroactively applied up to 5 years. So, a bill run generated in 2022 would need
-   * to consider every financial year back to 2017.
-   *
-   * The exception to that is the change in charge scheme that happened in 2022, when we moved from ALCS (or PRESROC) to
-   * SROC. Changes prior to 2022 would only apply to a ALCS bill run and vice versa.
-   *
-   * @returns {Object[]} an array of billing periods each containing a `startDate` and `endDate`.
-   */
-  static go () {
-    const currentDate = this._currentDate()
-    const currentYear = currentDate.getFullYear()
-
-    // 01-APR to 31-MAR
-    const financialPeriod = {
-      start: { day: 1, month: 3 },
-      end: { day: 31, month: 2 }
-    }
-
-    let startYear
-    let endYear
-
-    // IMPORANT! getMonth returns an integer (0-11). So, January is represented as 0 and December as 11. This is why
-    // financialPeriod.end.month is 2 rather than 3, even though we mean March
-    if (currentDate.getMonth() <= financialPeriod.end.month) {
-      // For example, if currentDate was 2022-02-15 it would fall in financial year 2021-04-01 to 2022-03-31
-      startYear = currentYear - 1
-      endYear = currentYear
-    } else {
-      // For example, if currentDate was 2022-06-15 it would fall in financial year 2022-04-01 to 2023-03-31
-      startYear = currentYear
-      endYear = currentYear + 1
-    }
-
-    return [{
-      startDate: new Date(startYear, financialPeriod.start.month, financialPeriod.start.day),
-      endDate: new Date(endYear, financialPeriod.end.month, financialPeriod.end.day)
-    }]
+/**
+ * Returns the billing periods needed when generating a supplementary bill run
+ *
+ * **IMPORANT!** This service currently only handles SROC billing periods and only the 'current year'
+ *
+ * Using the current date at the time the service is called, it calculates the billing periods to use. We permit
+ * changes to charge versions to be retroactively applied up to 5 years. So, a bill run generated in 2022 would need
+ * to consider every financial year back to 2017.
+ *
+ * The exception to that is the change in charge scheme that happened in 2022, when we moved from ALCS (or PRESROC) to
+ * SROC. Changes prior to 2022 would only apply to a ALCS bill run and vice versa.
+ *
+ * @returns {Object[]} an array of billing periods each containing a `startDate` and `endDate`.
+ */
+function go () {
+  const currentDate = new Date()
+  const currentYear = currentDate.getFullYear()
+
+  // 01-APR to 31-MAR
+  const financialPeriod = {
+    start: { day: 1, month: 3 },
+    end: { day: 31, month: 2 }
   }
 
-  static _currentDate () {
-    return new Date()
+  let startYear
+  let endYear
+
+  // IMPORANT! getMonth returns an integer (0-11). So, January is represented as 0 and December as 11. This is why
+  // financialPeriod.end.month is 2 rather than 3, even though we mean March
+  if (currentDate.getMonth() <= financialPeriod.end.month) {
+    // For example, if currentDate was 2022-02-15 it would fall in financial year 2021-04-01 to 2022-03-31
+    startYear = currentYear - 1
+    endYear = currentYear
+  } else {
+    // For example, if currentDate was 2022-06-15 it would fall in financial year 2022-04-01 to 2023-03-31
+    startYear = currentYear
+    endYear = currentYear + 1
   }
+
+  return [{
+    startDate: new Date(startYear, financialPeriod.start.month, financialPeriod.start.day),
+    endDate: new Date(endYear, financialPeriod.end.month, financialPeriod.end.day)
+  }]
 }
 
-module.exports = BillingPeriodService
+module.exports = {
+  go
+}
diff --git a/app/services/supplementary-billing/create-billing-batch.service.js b/app/services/supplementary-billing/create-billing-batch.service.js
index bb7c39a061..6a0db47031 100644
--- a/app/services/supplementary-billing/create-billing-batch.service.js
+++ b/app/services/supplementary-billing/create-billing-batch.service.js
@@ -7,29 +7,29 @@
 
 const BillingBatchModel = require('../../models/billing-batch.model.js')
 
-class CreateBillingBatchService {
-  /**
-   * Create a new billing batch
-   *
-   * @param {Object} [regionId] The region_id for the selected region
-   * @param {Object} [billingPeriod] The billing period in the format { startDate: 2022-04-01, endDate: 2023-03-31 }
-   *
-   * @returns {Object} The newly created billing batch record
-   */
-  static async go (regionId, billingPeriod) {
-    const billingBatch = await BillingBatchModel.query()
-      .insert({
-        region_id: regionId,
-        batch_type: 'supplementary',
-        from_financial_year_ending: billingPeriod.endDate.getFullYear(),
-        to_financial_year_ending: billingPeriod.endDate.getFullYear(),
-        status: 'processing',
-        scheme: 'sroc'
-      })
-      .returning('*')
+/**
+ * Create a new billing batch
+ *
+ * @param {Object} [regionId] The region_id for the selected region
+ * @param {Object} [billingPeriod] The billing period in the format { startDate: 2022-04-01, endDate: 2023-03-31 }
+ *
+ * @returns {Object} The newly created billing batch record
+ */
+async function go (regionId, billingPeriod) {
+  const billingBatch = await BillingBatchModel.query()
+    .insert({
+      region_id: regionId,
+      batch_type: 'supplementary',
+      from_financial_year_ending: billingPeriod.endDate.getFullYear(),
+      to_financial_year_ending: billingPeriod.endDate.getFullYear(),
+      status: 'processing',
+      scheme: 'sroc'
+    })
+    .returning('*')
 
-    return billingBatch
-  }
+  return billingBatch
 }
 
-module.exports = CreateBillingBatchService
+module.exports = {
+  go
+}
diff --git a/app/services/supplementary-billing/fetch-charge-versions.service.js b/app/services/supplementary-billing/fetch-charge-versions.service.js
index 416be60887..a1df9fe4d1 100644
--- a/app/services/supplementary-billing/fetch-charge-versions.service.js
+++ b/app/services/supplementary-billing/fetch-charge-versions.service.js
@@ -7,40 +7,40 @@
 
 const { db } = require('../../../db/db.js')
 
-class FetchChargeVersionsService {
-  /**
-   * Fetch all SROC charge versions linked to licences flagged for supplementary billing that are in the period being
-   * billed
-   *
-   * > This is not the final form of the service. It is a 'work in progress' as we implement tickets that gradually
-   * > build up our understanding of SROC supplementary billing
-   *
-   * @param {string} regionId GUID of the region which the licences will be linked to
-   * @param {Object} billingPeriod Object with a `startDate` and `endDate` property representing the period being billed
-   *
-   * @returns an array of Objects containing the relevant charge versions
-   */
-  static async go (regionId, billingPeriod) {
-    const chargeVersions = await this._fetch(regionId, billingPeriod)
+/**
+ * Fetch all SROC charge versions linked to licences flagged for supplementary billing that are in the period being
+ * billed
+ *
+ * > This is not the final form of the service. It is a 'work in progress' as we implement tickets that gradually
+ * > build up our understanding of SROC supplementary billing
+ *
+ * @param {string} regionId GUID of the region which the licences will be linked to
+ * @param {Object} billingPeriod Object with a `startDate` and `endDate` property representing the period being billed
+ *
+ * @returns an array of Objects containing the relevant charge versions
+ */
+async function go (regionId, billingPeriod) {
+  const chargeVersions = await _fetch(regionId, billingPeriod)
 
-    return chargeVersions
-  }
+  return chargeVersions
+}
 
-  static async _fetch (regionId, billingPeriod) {
-    const chargeVersions = db
-      .select('chv.chargeVersionId', 'chv.scheme', 'chv.startDate', 'chv.endDate', 'lic.licenceId', 'lic.licenceRef')
-      .from({ chv: 'water.charge_versions' })
-      .innerJoin({ lic: 'water.licences' }, 'chv.licence_id', 'lic.licence_id')
-      .where({
-        scheme: 'sroc',
-        'lic.include_in_supplementary_billing': 'yes',
-        'lic.region_id': regionId
-      })
-      .andWhere('chv.start_date', '>=', billingPeriod.startDate)
-      .andWhere('chv.start_date', '<=', billingPeriod.endDate)
+async function _fetch (regionId, billingPeriod) {
+  const chargeVersions = db
+    .select('chv.chargeVersionId', 'chv.scheme', 'chv.startDate', 'chv.endDate', 'lic.licenceId', 'lic.licenceRef')
+    .from({ chv: 'water.charge_versions' })
+    .innerJoin({ lic: 'water.licences' }, 'chv.licence_id', 'lic.licence_id')
+    .where({
+      scheme: 'sroc',
+      'lic.include_in_supplementary_billing': 'yes',
+      'lic.region_id': regionId
+    })
+    .andWhere('chv.start_date', '>=', billingPeriod.startDate)
+    .andWhere('chv.start_date', '<=', billingPeriod.endDate)
 
-    return chargeVersions
-  }
+  return chargeVersions
 }
 
-module.exports = FetchChargeVersionsService
+module.exports = {
+  go
+}
diff --git a/app/services/supplementary-billing/fetch-licences.service.js b/app/services/supplementary-billing/fetch-licences.service.js
index 583bf8b400..d07cc8df2f 100644
--- a/app/services/supplementary-billing/fetch-licences.service.js
+++ b/app/services/supplementary-billing/fetch-licences.service.js
@@ -7,32 +7,32 @@
 
 const LicenceModel = require('../../models/licence.model.js')
 
-class FetchLicencesService {
-  /**
-   * Fetches licences flagged for supplementary billing that are linked to the selected region
-   *
-   * This is a temporary service to help us confirm we are selecting the correct data to use when creating a
-   * supplementary bill run. Its primary aim is to meet the acceptance criteria defined in WATER-3787.
-   *
-   * @param {Object} region Instance of `RegionModel` for the selected region
-   *
-   * @returns {Object[]} Array of matching `LicenceModel`
-   */
-  static async go (region) {
-    const licences = await this._fetch(region)
+/**
+ * Fetches licences flagged for supplementary billing that are linked to the selected region
+ *
+ * This is a temporary service to help us confirm we are selecting the correct data to use when creating a
+ * supplementary bill run. Its primary aim is to meet the acceptance criteria defined in WATER-3787.
+ *
+ * @param {Object} region Instance of `RegionModel` for the selected region
+ *
+ * @returns {Object[]} Array of matching `LicenceModel`
+ */
+async function go (region) {
+  const licences = await _fetch(region)
 
-    return licences
-  }
+  return licences
+}
 
-  static async _fetch (region) {
-    const result = await LicenceModel.query()
-      .innerJoinRelated('chargeVersions')
-      .where('region_id', region.regionId)
-      .where('include_in_supplementary_billing', 'yes')
-      .where('chargeVersions.scheme', 'sroc')
+async function _fetch (region) {
+  const result = await LicenceModel.query()
+    .innerJoinRelated('chargeVersions')
+    .where('region_id', region.regionId)
+    .where('include_in_supplementary_billing', 'yes')
+    .where('chargeVersions.scheme', 'sroc')
 
-    return result
-  }
+  return result
 }
 
-module.exports = FetchLicencesService
+module.exports = {
+  go
+}
diff --git a/app/services/supplementary-billing/fetch-region.service.js b/app/services/supplementary-billing/fetch-region.service.js
index c6b926626a..0705534cd6 100644
--- a/app/services/supplementary-billing/fetch-region.service.js
+++ b/app/services/supplementary-billing/fetch-region.service.js
@@ -7,31 +7,31 @@
 
 const RegionModel = require('../../models/region.model.js')
 
-class FetchRegionService {
-  /**
-   * Fetches the region with the matching NALD Region ID
-   *
-   * This is a temporary service to help us confirm we are selecting the correct data to use when creating a
-   * supplementary bill run. Its primary aim is to meet the acceptance criteria defined in WATER-3787.
-   *
-   * @param {string} naldRegionId The NALD region ID (a number between 1 to 9, 9 being the test region) for the region
-   * to find
-   *
-   * @returns {Object} Instance of `RegionModel` with the matching NALD Region ID
-   */
-  static async go (naldRegionId) {
-    const region = await this._fetch(naldRegionId)
+/**
+ * Fetches the region with the matching NALD Region ID
+ *
+ * This is a temporary service to help us confirm we are selecting the correct data to use when creating a
+ * supplementary bill run. Its primary aim is to meet the acceptance criteria defined in WATER-3787.
+ *
+ * @param {string} naldRegionId The NALD region ID (a number between 1 to 9, 9 being the test region) for the region
+ * to find
+ *
+ * @returns {Object} Instance of `RegionModel` with the matching NALD Region ID
+ */
+async function go (naldRegionId) {
+  const region = await _fetch(naldRegionId)
 
-    return region
-  }
+  return region
+}
 
-  static async _fetch (naldRegionId) {
-    const result = await RegionModel.query()
-      .where('nald_region_id', naldRegionId)
-      .first()
+async function _fetch (naldRegionId) {
+  const result = await RegionModel.query()
+    .where('nald_region_id', naldRegionId)
+    .first()
 
-    return result
-  }
+  return result
 }
 
-module.exports = FetchRegionService
+module.exports = {
+  go
+}
diff --git a/app/services/supplementary-billing/supplementary.service.js b/app/services/supplementary-billing/supplementary.service.js
index 5aba11a7bf..5208fda9f4 100644
--- a/app/services/supplementary-billing/supplementary.service.js
+++ b/app/services/supplementary-billing/supplementary.service.js
@@ -2,6 +2,9 @@
 
 /**
  * Determines the billing periods, licences and charge versions used to generate an SROC supplementary bill run
+ *
+ * WIP: This is currently being used to generate testing data to confirm we are understanding SROC supplementary
+ * billing. We intend to refactor things so that the service starts representing what is actually required.
  * @module SupplementaryService
  */
 
@@ -11,30 +14,24 @@ const FetchLicencesService = require('./fetch-licences.service.js')
 const FetchRegionService = require('./fetch-region.service.js')
 const SupplementaryPresenter = require('../../presenters/supplementary.presenter.js')
 
-/**
- * WIP: This is currently being used to generate testing data to confirm we are understanding SROC supplementary
- * billing. We intend to refactor things so that the service starts representing what is actually required.
- */
-class SupplementaryService {
-  static async go (naldRegionId) {
-    const region = await FetchRegionService.go(naldRegionId)
-    const billingPeriods = BillingPeriodService.go()
-    const licences = await FetchLicencesService.go(region)
-
-    // We know in the future we will be calculating multiple billing periods and so will have to iterate through each,
-    // generating bill runs and reviewing if there is anything to bill. For now, whilst our knowledge of the process
-    // is low we are focusing on just the current financial year, and intending to ship a working version for just it.
-    // This is why we are only passing through the first billing period; we know there is only one!
-    const chargeVersions = await FetchChargeVersionsService.go(region.regionId, billingPeriods[0])
+async function go (naldRegionId) {
+  const region = await FetchRegionService.go(naldRegionId)
+  const billingPeriods = BillingPeriodService.go()
+  const licences = await FetchLicencesService.go(region)
 
-    return this._response({ billingPeriods, licences, chargeVersions })
-  }
+  // We know in the future we will be calculating multiple billing periods and so will have to iterate through each,
+  // generating bill runs and reviewing if there is anything to bill. For now, whilst our knowledge of the process
+  // is low we are focusing on just the current financial year, and intending to ship a working version for just it.
+  // This is why we are only passing through the first billing period; we know there is only one!
+  const chargeVersions = await FetchChargeVersionsService.go(region.regionId, billingPeriods[0])
 
-  static _response (data) {
-    const presenter = new SupplementaryPresenter(data)
+  return _response({ billingPeriods, licences, chargeVersions })
+}
 
-    return presenter.go()
-  }
+function _response (data) {
+  return SupplementaryPresenter.go(data)
 }
 
-module.exports = SupplementaryService
+module.exports = {
+  go
+}
diff --git a/test/presenters/supplementary.presenter.test.js b/test/presenters/supplementary.presenter.test.js
index dc5dcfb55c..80847d2e9d 100644
--- a/test/presenters/supplementary.presenter.test.js
+++ b/test/presenters/supplementary.presenter.test.js
@@ -44,8 +44,7 @@ describe('Supplementary presenter', () => {
     })
 
     it('correctly presents the data', () => {
-      const presenter = new SupplementaryPresenter(data)
-      const result = presenter.go()
+      const result = SupplementaryPresenter.go(data)
 
       expect(result.billingPeriods).to.have.length(1)
       expect(result.billingPeriods[0]).to.equal(data.billingPeriods[0])
@@ -71,8 +70,7 @@ describe('Supplementary presenter', () => {
     })
 
     it('correctly presents the data', () => {
-      const presenter = new SupplementaryPresenter(data)
-      const result = presenter.go()
+      const result = SupplementaryPresenter.go(data)
 
       expect(result.billingPeriods).to.be.empty()
       expect(result.licences).to.be.empty()
diff --git a/test/services/supplementary-billing/billing-period.service.test.js b/test/services/supplementary-billing/billing-period.service.test.js
index fe74618301..563171a44f 100644
--- a/test/services/supplementary-billing/billing-period.service.test.js
+++ b/test/services/supplementary-billing/billing-period.service.test.js
@@ -12,19 +12,24 @@ const { expect } = Code
 const BillingPeriodService = require('../../../app/services/supplementary-billing/billing-period.service.js')
 
 describe('Billing Period service', () => {
+  let clock
+  let expectedResult
+  let testDate
+
   afterEach(() => {
+    clock.restore()
     Sinon.restore()
   })
 
   describe('when the date is in 2022 and falls within the 2022 financial year', () => {
-    const testDate = new Date('2022-04-01')
-    const expectedResult = {
-      startDate: new Date('2022-04-01'),
-      endDate: new Date('2023-03-31')
-    }
-
     beforeEach(async () => {
-      Sinon.stub(BillingPeriodService, '_currentDate').returns(testDate)
+      testDate = new Date('2022-04-01')
+      expectedResult = {
+        startDate: new Date('2022-04-01'),
+        endDate: new Date('2023-03-31')
+      }
+
+      clock = Sinon.useFakeTimers(testDate)
     })
 
     it('returns the expected date range', () => {
@@ -36,14 +41,14 @@ describe('Billing Period service', () => {
   })
 
   describe('when the date is in 2023 and falls within the 2022 financial year', () => {
-    const testDate = new Date('2023-03-01')
-    const expectedResult = {
-      startDate: new Date('2022-04-01'),
-      endDate: new Date('2023-03-31')
-    }
-
     beforeEach(async () => {
-      Sinon.stub(BillingPeriodService, '_currentDate').returns(testDate)
+      testDate = new Date('2023-03-01')
+      expectedResult = {
+        startDate: new Date('2022-04-01'),
+        endDate: new Date('2023-03-31')
+      }
+
+      clock = Sinon.useFakeTimers(testDate)
     })
 
     it('returns the expected date range', () => {
@@ -55,14 +60,14 @@ describe('Billing Period service', () => {
   })
 
   describe('when the date is in 2023 and falls within the 2023 financial year', () => {
-    const testDate = new Date('2023-10-10')
-    const expectedResult = {
-      startDate: new Date('2023-04-01'),
-      endDate: new Date('2024-03-31')
-    }
-
     beforeEach(async () => {
-      Sinon.stub(BillingPeriodService, '_currentDate').returns(testDate)
+      testDate = new Date('2023-10-10')
+      expectedResult = {
+        startDate: new Date('2023-04-01'),
+        endDate: new Date('2024-03-31')
+      }
+
+      clock = Sinon.useFakeTimers(testDate)
     })
 
     it('returns the expected date range', () => {
@@ -72,12 +77,4 @@ describe('Billing Period service', () => {
       expect(result[0]).to.equal(expectedResult)
     })
   })
-
-  describe('when the _currentDate function is not stubbed', () => {
-    it('returns a date range', () => {
-      const result = BillingPeriodService.go()
-
-      expect(result.length).to.equal(1)
-    })
-  })
 })
diff --git a/test/support/helpers/charge-version.helper.js b/test/support/helpers/charge-version.helper.js
index 9df8cb4b9d..55cfc6924b 100644
--- a/test/support/helpers/charge-version.helper.js
+++ b/test/support/helpers/charge-version.helper.js
@@ -8,66 +8,67 @@ const { db } = require('../../../db/db.js')
 
 const LicenceHelper = require('./licence.helper.js')
 
-class ChargeVersionHelper {
-  /**
-   * Add a new charge version
-   *
-   * A charge version is always linked to a licence. So, creating a charge version will automatically create a new
-   * licence and handle linking the two together by `licence_id`.
-   *
-   * If no `data` is provided, default values will be used. These are
-   *
-   * - `scheme` - sroc
-   * - `licence_ref` - 01/123
-   *
-   * See `LicenceHelper` for the licence defaults
-   *
-   * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
-   * @param {Object} [licence] Any licence data you want to use instead of the defaults used here or in the database
-   *
-   * @returns {string} The ID of the newly created record
-   */
-  static async add (data = {}, licence = {}) {
-    let licenceId = licence?.licenceId
-    if (!licenceId) {
-      licenceId = await this._addLicence(licence)
-    }
+/**
+ * Add a new charge version
+ *
+ * A charge version is always linked to a licence. So, creating a charge version will automatically create a new
+ * licence and handle linking the two together by `licence_id`.
+ *
+ * If no `data` is provided, default values will be used. These are
+ *
+ * - `scheme` - sroc
+ * - `licence_ref` - 01/123
+ *
+ * See `LicenceHelper` for the licence defaults
+ *
+ * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
+ * @param {Object} [licence] Any licence data you want to use instead of the defaults used here or in the database
+ *
+ * @returns {string} The ID of the newly created record
+ */
+async function add (data = {}, licence = {}) {
+  let licenceId = licence?.licenceId
+  if (!licenceId) {
+    licenceId = await _addLicence(licence)
+  }
 
-    const insertData = this.defaults({ ...data, licence_id: licenceId })
+  const insertData = defaults({ ...data, licence_id: licenceId })
 
-    const result = await db.table('water.charge_versions')
-      .insert(insertData)
-      .returning('charge_version_id')
+  const result = await db.table('water.charge_versions')
+    .insert(insertData)
+    .returning('charge_version_id')
 
-    return result
-  }
+  return result
+}
 
-  /**
-   * Returns the defaults used when creating a new charge version
-   *
-   * It will override or append to them any data provided. Mainly used by the `add()` method, we make it available
-   * for use in tests to avoid having to duplicate values.
-   *
-   * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
-   */
-  static defaults (data = {}) {
-    const defaults = {
-      licence_ref: '01/123',
-      scheme: 'sroc',
-      start_date: new Date('2022-04-01')
-    }
+/**
+ * Returns the defaults used when creating a new charge version
+ *
+ * It will override or append to them any data provided. Mainly used by the `add()` method, we make it available
+ * for use in tests to avoid having to duplicate values.
+ *
+ * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
+ */
+function defaults (data = {}) {
+  const defaults = {
+    licence_ref: '01/123',
+    scheme: 'sroc',
+    start_date: new Date('2022-04-01')
+  }
 
-    return {
-      ...defaults,
-      ...data
-    }
+  return {
+    ...defaults,
+    ...data
   }
+}
 
-  static async _addLicence (licence) {
-    const result = await LicenceHelper.add(licence)
+async function _addLicence (licence) {
+  const result = await LicenceHelper.add(licence)
 
-    return result[0].licenceId
-  }
+  return result[0].licenceId
 }
 
-module.exports = ChargeVersionHelper
+module.exports = {
+  add,
+  defaults
+}
diff --git a/test/support/helpers/database.helper.js b/test/support/helpers/database.helper.js
index 051c0d4dee..c79a26db07 100644
--- a/test/support/helpers/database.helper.js
+++ b/test/support/helpers/database.helper.js
@@ -1,42 +1,40 @@
 'use strict'
 
 /**
+ * Use to help with cleaning the database between tests
+ *
+ * It's good practise to ensure the database is in a 'clean' state between tests to avoid any side effects caused by
+ * data from one test being present in another.
  * @module DatabaseHelper
  */
 
 const { db } = require('../../../db/db.js')
 
 /**
- * Use to help with cleaning the database between tests
+ * Call to clean the database of all data
  *
- * It's good practise to ensure the database is in a 'clean' state between tests to avoid any side effects caused by
- * data from one test being present in another.
+ * It works by identifying all the tables in each schema which we use.
+ *
+ * Once it has that info it creates a query that tells PostgreSQL to TRUNCATE all the tables and restart their
+ * identity columns. For example, if a table relies on an incrementing ID the query will reset that to 1.
  */
-class DatabaseHelper {
-  /**
-   * Call to clean the database of all data
-   *
-   * It works by identifying all the tables in each schema which we use.
-   *
-   * Once it has that info it creates a query that tells PostgreSQL to TRUNCATE all the tables and restart their
-   * identity columns. For example, if a table relies on an incrementing ID the query will reset that to 1.
-   */
-  static async clean () {
-    const schemas = ['water']
+async function clean () {
+  const schemas = ['water']
 
-    for (const schema of schemas) {
-      const tables = await this._tableNames(schema)
-      await db.raw(`TRUNCATE TABLE ${tables.join(',')} RESTART IDENTITY`)
-    }
+  for (const schema of schemas) {
+    const tables = await _tableNames(schema)
+    await db.raw(`TRUNCATE TABLE ${tables.join(',')} RESTART IDENTITY`)
   }
+}
 
-  static async _tableNames (schema) {
-    const result = await db('pg_tables')
-      .select('tablename')
-      .where('schemaname', schema)
+async function _tableNames (schema) {
+  const result = await db('pg_tables')
+    .select('tablename')
+    .where('schemaname', schema)
 
-    return result.map((table) => `${schema}.${table.tablename}`)
-  }
+  return result.map((table) => `${schema}.${table.tablename}`)
 }
 
-module.exports = DatabaseHelper
+module.exports = {
+  clean
+}
diff --git a/test/support/helpers/licence.helper.js b/test/support/helpers/licence.helper.js
index 461996440d..072c8b078f 100644
--- a/test/support/helpers/licence.helper.js
+++ b/test/support/helpers/licence.helper.js
@@ -6,48 +6,49 @@
 
 const { db } = require('../../../db/db.js')
 
-class LicenceHelper {
-  /**
-   * Add a new licence
-   *
-   * If no `data` is provided, default values will be used. These are
-   *
-   * - `licence_ref` - 01/123
-   * - `region_id` - bd114474-790f-4470-8ba4-7b0cc9c225d7
-   *
-   * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
-   *
-   * @returns {string} The ID of the newly created record
-   */
-  static async add (data = {}) {
-    const insertData = this.defaults(data)
-
-    const result = await db.table('water.licences')
-      .insert(insertData)
-      .returning('licence_id')
-
-    return result
+/**
+ * Add a new licence
+ *
+ * If no `data` is provided, default values will be used. These are
+ *
+ * - `licence_ref` - 01/123
+ * - `region_id` - bd114474-790f-4470-8ba4-7b0cc9c225d7
+ *
+ * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
+ *
+ * @returns {string} The ID of the newly created record
+ */
+async function add (data = {}) {
+  const insertData = defaults(data)
+
+  const result = await db.table('water.licences')
+    .insert(insertData)
+    .returning('licence_id')
+
+  return result
+}
+
+/**
+ * Returns the defaults used when creating a new licence
+ *
+ * It will override or append to them any data provided. Mainly used by the `add()` method, we make it available
+ * for use in tests to avoid having to duplicate values.
+ *
+ * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
+ */
+function defaults (data = {}) {
+  const defaults = {
+    licence_ref: '01/123',
+    region_id: 'bd114474-790f-4470-8ba4-7b0cc9c225d7'
   }
 
-  /**
-   * Returns the defaults used when creating a new licence
-   *
-   * It will override or append to them any data provided. Mainly used by the `add()` method, we make it available
-   * for use in tests to avoid having to duplicate values.
-   *
-   * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
-   */
-  static defaults (data = {}) {
-    const defaults = {
-      licence_ref: '01/123',
-      region_id: 'bd114474-790f-4470-8ba4-7b0cc9c225d7'
-    }
-
-    return {
-      ...defaults,
-      ...data
-    }
+  return {
+    ...defaults,
+    ...data
   }
 }
 
-module.exports = LicenceHelper
+module.exports = {
+  add,
+  defaults
+}
diff --git a/test/support/helpers/region.helper.js b/test/support/helpers/region.helper.js
index da89cb9c42..1434eda4bd 100644
--- a/test/support/helpers/region.helper.js
+++ b/test/support/helpers/region.helper.js
@@ -6,48 +6,49 @@
 
 const { db } = require('../../../db/db.js')
 
-class RegionHelper {
-  /**
-   * Add a new region
-   *
-   * If no `data` is provided, default values will be used. These are
-   *
-   * - `charge_region_id` - S
-   * - `nald_region_id` - 9
-   *
-   * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
-   *
-   * @returns {string} The ID of the newly created record
-   */
-  static async add (data = {}) {
-    const insertData = this.defaults(data)
-
-    const result = await db.table('water.regions')
-      .insert(insertData)
-      .returning('region_id')
-
-    return result
+/**
+ * Add a new region
+ *
+ * If no `data` is provided, default values will be used. These are
+ *
+ * - `charge_region_id` - S
+ * - `nald_region_id` - 9
+ *
+ * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
+ *
+ * @returns {string} The ID of the newly created record
+ */
+async function add (data = {}) {
+  const insertData = defaults(data)
+
+  const result = await db.table('water.regions')
+    .insert(insertData)
+    .returning('region_id')
+
+  return result
+}
+
+/**
+ * Returns the defaults used when creating a new region
+ *
+ * It will override or append to them any data provided. Mainly used by the `add()` method, we make it available
+ * for use in tests to avoid having to duplicate values.
+ *
+ * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
+ */
+function defaults (data = {}) {
+  const defaults = {
+    charge_region_id: 'S',
+    nald_region_id: 9
   }
 
-  /**
-   * Returns the defaults used when creating a new region
-   *
-   * It will override or append to them any data provided. Mainly used by the `add()` method, we make it available
-   * for use in tests to avoid having to duplicate values.
-   *
-   * @param {Object} [data] Any data you want to use instead of the defaults used here or in the database
-   */
-  static defaults (data = {}) {
-    const defaults = {
-      charge_region_id: 'S',
-      nald_region_id: 9
-    }
-
-    return {
-      ...defaults,
-      ...data
-    }
+  return {
+    ...defaults,
+    ...data
   }
 }
 
-module.exports = RegionHelper
+module.exports = {
+  add,
+  defaults
+}