diff --git a/custom-words.txt b/custom-words.txt
index 424af84e7c41..2cf188a4b212 100644
--- a/custom-words.txt
+++ b/custom-words.txt
@@ -1509,6 +1509,7 @@ ukwest
 Ulaanbaatar
 unallocated
 unattend
+unbilled
 Unclaim
 Undelete
 undeleted
diff --git a/specification/billing/resource-manager/Microsoft.Billing/preview/2019-10-01-preview/billing.json b/specification/billing/resource-manager/Microsoft.Billing/preview/2019-10-01-preview/billing.json
index 51db4fb34e87..3f7c002c9e65 100644
--- a/specification/billing/resource-manager/Microsoft.Billing/preview/2019-10-01-preview/billing.json
+++ b/specification/billing/resource-manager/Microsoft.Billing/preview/2019-10-01-preview/billing.json
@@ -1312,7 +1312,7 @@
           "Transactions"
         ],
         "operationId": "Transactions_ListByCustomer",
-        "description": "Lists the transactions by customer id for given start date and end date.",
+        "description": "Lists the billed and unbilled transactions by customer id for given start date and end date. Transactions include purchases, refunds and Azure usage charges. Unbilled transactions are listed under pending invoice Id and do not include tax. Tax is added to the amount once an invoice is generated.",
         "externalDocs": {
           "url": "https://docs.microsoft.com/en-us/rest/api/consumption/"
         },
@@ -2528,7 +2528,7 @@
           "Transactions"
         ],
         "operationId": "Transactions_ListByBillingAccount",
-        "description": "Lists the transactions by billing account name for given start and end date.",
+        "description": "Lists the billed and unbilled transactions by billing account name for given start and end date. Transactions include purchases, refunds and Azure usage charges. Unbilled transactions are listed under pending invoice ID and do not include tax. Tax is added to the amount once an invoice is generated.",
         "externalDocs": {
           "url": "https://docs.microsoft.com/en-us/rest/api/billing/"
         },
@@ -2594,7 +2594,7 @@
           "Transactions"
         ],
         "operationId": "Transactions_ListByBillingProfile",
-        "description": "Lists the transactions by billing profile name for given start date and end date.",
+        "description": "Lists the billed and unbilled transactions by billing profile name for given start date and end date. Transactions include purchases, refunds and Azure usage charges. Unbilled transactions are listed under pending invoice Id and do not include tax. Tax is added to the amount once an invoice is generated.",
         "externalDocs": {
           "url": "https://docs.microsoft.com/en-us/rest/api/billing/"
         },
@@ -2660,7 +2660,7 @@
           "Transactions"
         ],
         "operationId": "Transactions_ListByInvoiceSection",
-        "description": "Lists the transactions by invoice section name for given start date and end date.",
+        "description": "Lists the billed and unbilled transactions by invoice section name for given start date and end date. Transactions include purchases, refunds and Azure usage charges. Unbilled transactions are listed under pending invoice Id and do not include tax. Tax is added to the amount once an invoice is generated.",
         "externalDocs": {
           "url": "https://docs.microsoft.com/en-us/rest/api/billing/"
         },
@@ -2723,6 +2723,54 @@
         }
       }
     },
+    "/providers/Microsoft.Billing/billingAccounts/{billingAccountName}/billingProfiles/{billingProfileName}/invoices/{invoiceName}/transactions": {
+      "get": {
+        "tags": [
+          "Transactions"
+        ],
+        "operationId": "Transactions_ListByInvoice",
+        "description": "Lists the transactions by invoice. Transactions include purchases, refunds and Azure usage charges.",
+        "externalDocs": {
+          "url": "https://docs.microsoft.com/en-us/rest/api/billing/"
+        },
+        "x-ms-examples": {
+          "TransactionsListByInvoice": {
+            "$ref": "./examples/TransactionsListByInvoice.json"
+          }
+        },
+        "parameters": [
+          {
+            "$ref": "#/parameters/billingAccountNameParameter"
+          },
+          {
+            "$ref": "#/parameters/billingProfileNameParameter"
+          },
+          {
+            "$ref": "#/parameters/invoiceNameParameter"
+          },
+          {
+            "$ref": "#/parameters/apiVersionParameter"
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "OK. The request has succeeded.",
+            "schema": {
+              "$ref": "#/definitions/TransactionListResult"
+            }
+          },
+          "default": {
+            "description": "Error response describing why the operation failed.",
+            "schema": {
+              "$ref": "#/definitions/ErrorResponse"
+            }
+          }
+        },
+        "x-ms-pageable": {
+          "nextLinkName": "nextLink"
+        }
+      }
+    },
     "/providers/Microsoft.Billing/billingAccounts/{billingAccountName}/billingProfiles/{billingProfileName}/transactions/{transactionName}": {
       "get": {
         "tags": [
diff --git a/specification/billing/resource-manager/Microsoft.Billing/preview/2019-10-01-preview/examples/TransactionsListByInvoice.json b/specification/billing/resource-manager/Microsoft.Billing/preview/2019-10-01-preview/examples/TransactionsListByInvoice.json
new file mode 100644
index 000000000000..7c1da9f1e531
--- /dev/null
+++ b/specification/billing/resource-manager/Microsoft.Billing/preview/2019-10-01-preview/examples/TransactionsListByInvoice.json
@@ -0,0 +1,122 @@
+{
+  "parameters": {
+    "api-version": "2019-10-01-preview",
+    "billingAccountName": "{billingAccountName}",
+    "billingProfileName": "{billingProfileName}",
+    "invoiceName": "{invoiceName}"
+  },
+  "responses": {
+    "200": {
+      "body": {
+        "value": [
+          {
+            "id": "/providers/Microsoft.Billing/BillingAccounts/{billingAccountName}/BillingProfiles/{billingProfileName}/transactions/41000000-0000-0000-0000-000000000000",
+            "name": "41000000-0000-0000-0000-000000000000",
+            "type": "Microsoft.Billing/billingAccounts/billingProfiles/transactions",
+            "properties": {
+              "kind": "all",
+              "date": "2018-05-01T00:00:00Z",
+              "invoice": "2344233",
+              "productFamily": "Storage",
+              "productTypeId": "A12345",
+              "productType": "VM Instance",
+              "productDescription": "Standard D1, US West 3",
+              "transactionType": "Purchase",
+              "transactionAmount": {
+                "currency": "USD",
+                "value": 5000.00
+              },
+              "invoiceSectionId": "/providers/Microsoft.Billing/billingAccounts/{billingAccountName}/billingProfiles/{billingProfileName}/invoiceSections/22000000-0000-0000-0000-000000000000",
+              "invoiceSectionDisplayName": "Contoso operations invoiceSection",
+              "billingProfileId": "/providers/Microsoft.Billing/billingAccounts/{billingAccountName}/billingProfiles/{billingProfileName}",
+              "billingProfileDisplayName": "Contoso operations billing",
+              "azureCreditApplied": {
+                "currency": "USD",
+                "value": 2000.00
+              },
+              "billingCurrency": "USD",
+              "discount": 0.1,
+              "effectivePrice": {
+                "currency": "USD",
+                "value": 10.00
+              },
+              "exchangeRate": 1,
+              "marketPrice": {
+                "currency": "USD",
+                "value": 20.00
+              },
+              "pricingCurrency": "USD",
+              "quantity": 1,
+              "servicePeriodStartDate": "2018-05-01T00:00:00Z",
+              "servicePeriodEndDate": "2018-09-30T00:00:00Z",
+              "subTotal": {
+                "currency": "USD",
+                "value": 4500.00
+              },
+              "tax": {
+                "currency": "USD",
+                "value": 500.00
+              },
+              "unitOfMeasure": "1 Minute",
+              "units": 11.25,
+              "unitType": "1 Runtime Minute"
+            }
+          },
+          {
+            "id": "/providers/Microsoft.Billing/BillingAccounts/{billingAccountName}/BillingProfiles/{billingProfileName}/transactions/51000000-0000-0000-0000-000000000000",
+            "name": "51000000-0000-0000-0000-000000000000",
+            "type": "Microsoft.Billing/billingAccounts/billingProfiles/transactions",
+            "properties": {
+              "kind": "all",
+              "date": "2018-04-01T00:00:00Z",
+              "invoice": "pending",
+              "productFamily": "Storage",
+              "productTypeId": "A12345",
+              "productType": "VM Instance",
+              "productDescription": "Standard Support",
+              "transactionType": "Cancel",
+              "transactionAmount": {
+                "currency": "USD",
+                "value": 50.00
+              },
+              "invoiceSectionId": "/providers/Microsoft.Billing/billingAccounts/{billingAccountName}/billingProfiles/{billingProfileName}/invoiceSections/22000000-0000-0000-0000-000000000000",
+              "invoiceSectionDisplayName": "Contoso operations invoiceSection",
+              "billingProfileId": "/providers/Microsoft.Billing/billingAccounts/{billingAccountName}/billingProfiles/{billingProfileName}",
+              "billingProfileDisplayName": "Contoso operations billing",
+              "azureCreditApplied": {
+                "currency": "USD",
+                "value": 20.00
+              },
+              "billingCurrency": "USD",
+              "discount": 0.1,
+              "effectivePrice": {
+                "currency": "USD",
+                "value": 10.00
+              },
+              "exchangeRate": 1,
+              "marketPrice": {
+                "currency": "USD",
+                "value": 20.00
+              },
+              "pricingCurrency": "USD",
+              "quantity": 1,
+              "servicePeriodStartDate": "2018-05-01T00:00:00Z",
+              "servicePeriodEndDate": "2018-09-30T00:00:00Z",
+              "subTotal": {
+                "currency": "USD",
+                "value": 45.00
+              },
+              "tax": {
+                "currency": "USD",
+                "value": 5.00
+              },
+              "unitOfMeasure": "1 Minute",
+              "units": 1.25,
+              "unitType": "1 Runtime Minute"
+            }
+          }
+        ]
+      }
+    }
+  }
+}