diff --git a/README.md b/README.md
index c967471..1d77dde 100644
--- a/README.md
+++ b/README.md
@@ -57,6 +57,10 @@ By default, this action will allow any valid Issue Key so long as it *could* be
 
 A specific Project Key to always check for
 
+### `projectKeys`
+
+Multiple Project Keys to always check for
+
 ### `separator`
 
 A specific separator to use. Defaults to a space character.
@@ -65,6 +69,9 @@ A specific separator to use. Defaults to a space character.
 
 Allows the Jira Project Key, Issue # and separator to be anywhere in the title. Defaults to false.
 
+
+Note that `projectKey` and `projectKeys` works same under the hood. You can pass either one of them depending on the usecase.
+
 ## Example Usage
 
 ```
@@ -81,6 +88,18 @@ Allows the Jira Project Key, Issue # and separator to be anywhere in the title.
     projectKey: 'AB'
 ```
 
+## Example Usage with a multiple Project Keys
+
+```
+- name: Enforce Jira Issue Key in Pull Request Title
+  uses: ryanvade/enforce-pr-title-style-action@v2
+  with:
+    projectKeys: |
+      'AB'
+      'CD'
+      'EF'
+```
+
 ## Example Usage with a specific Project Key and a separator
 
 ```
diff --git a/__tests__/index.test.ts b/__tests__/index.test.ts
index 31702ac..6d569e4 100644
--- a/__tests__/index.test.ts
+++ b/__tests__/index.test.ts
@@ -3,12 +3,15 @@ import { readFileSync } from "fs";
 import { getPullRequestTitle, getRegex } from "../src/main";
 
 const projectKeyInputName = "projectKey";
+const projectKeysInputName = 'projectKeys';
 const separatorKeyInputName = "separator";
 const keyAnywhereInTitle = "keyAnywhereInTitle";
 
 const resetEnvironmentVariables = () => {
   process.env[`INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`] =
     "";
+  process.env[`INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`] =
+    "";
   process.env[
     `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
   ] = "";
@@ -47,98 +50,271 @@ describe("index", () => {
 
   describe("getRegex", () => {
     beforeEach(() => resetEnvironmentVariables());
-    it("gets the default when no project key is provided", () => {
-      process.env[
-        `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
-      ] = "";
-      const regex = getRegex();
-      const defaultRegex =
-        // eslint-disable-next-line no-useless-escape
-        /(?<=^|[a-z]-|[\s\p{Punct}&[^\-]])([A-Z][A-Z0-9_]*-\d+)(?![^\W_])(\s)+(.)+/;
-      expect(regex).toEqual(defaultRegex);
-      expect(regex.test("PR-4 this is valid")).toBe(true);
-    });
+    describe("when projectKey is provided", () => {
+      it("uses a project key if it exists", () => {
+        process.env[
+          `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB";
+        const regex = getRegex();
+        expect(regex.length).toEqual(1);
+        expect(regex[0]).toEqual(new RegExp(`(^AB-){1}(\\d)+(\\s)+(.)+`));
+        expect(regex[0].test("AB-43 stuff and things")).toBe(true);
+      });
 
-    it("uses a project key if it exists", () => {
-      process.env[
-        `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
-      ] = "AB";
-      const regex = getRegex();
-      expect(regex).toEqual(new RegExp(`(^AB-){1}(\\d)+(\\s)+(.)+`));
-      expect(regex.test("AB-43 stuff and things")).toBe(true);
-    });
+      it("throws an exception if the provided project key is not valid", () => {
+        process.env[
+          `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "aB";
+        expect(getRegex).toThrow('Project Key  "aB" is invalid');
+      });
 
-    it("throws an exception if the provided project key is not valid", () => {
-      process.env[
-        `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
-      ] = "aB";
-      expect(getRegex).toThrow('Project Key  "aB" is invalid');
-    });
+      it("uses a project key and a colon separator if they exist", () => {
+        process.env[
+          `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB";
+        process.env[
+          `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = ":";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "false";
+        const regex = getRegex();
+        expect(regex.length).toEqual(1);
+        expect(regex[0]).toEqual(new RegExp(`(^AB-){1}(\\d)+(:)+(\\S)+(.)+`));
+        expect(regex[0].test("AB-43: stuff and things")).toBe(false);
+        expect(regex[0].test("AB-123: PR Title")).toBe(false);
+        expect(regex[0].test("AB-43:stuff and things")).toBe(true);
+        expect(regex[0].test("AB-123:PR Title")).toBe(true);
+      });
 
-    it("uses a project key and a colon separator if they exist", () => {
-      process.env[
-        `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
-      ] = "AB";
-      process.env[
-        `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
-      ] = ":";
-      process.env[
-        `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
-      ] = "false";
-      const regex = getRegex();
-      expect(regex).toEqual(new RegExp(`(^AB-){1}(\\d)+(:)+(\\S)+(.)+`));
-      expect(regex.test("AB-43: stuff and things")).toBe(false);
-      expect(regex.test("AB-123: PR Title")).toBe(false);
-      expect(regex.test("AB-43:stuff and things")).toBe(true);
-      expect(regex.test("AB-123:PR Title")).toBe(true);
-    });
+      it("uses a project key and an underscore separator if they exist", () => {
+        process.env[
+          `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB";
+        process.env[
+          `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "_";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "false";
+        const regex = getRegex();
+        expect(regex.length).toEqual(1);
+        expect(regex[0]).toEqual(new RegExp(`(^AB-){1}(\\d)+(_)+(\\S)+(.)+`));
+        expect(regex[0].test("AB-43_stuff and things")).toBe(true);
+        expect(regex[0].test("AB-123_PR Title")).toBe(true);
+      });
 
-    it("uses a project key and an underscore separator if they exist", () => {
-      process.env[
-        `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
-      ] = "AB";
-      process.env[
-        `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
-      ] = "_";
-      process.env[
-        `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
-      ] = "false";
-      const regex = getRegex();
-      expect(regex).toEqual(new RegExp(`(^AB-){1}(\\d)+(_)+(\\S)+(.)+`));
-      expect(regex.test("AB-43_stuff and things")).toBe(true);
-      expect(regex.test("AB-123_PR Title")).toBe(true);
-    });
+      it("uses a project key if it exists anywhere in the title", () => {
+        process.env[
+          `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "true";
+        const regex = getRegex();
+        expect(regex.length).toEqual(1);
+        expect(regex[0]).toEqual(new RegExp(`(.)*(AB-){1}(\\d)+(\\s)+(.)+`));
+        expect(regex[0].test("other words AB-43 stuff and things")).toBe(true);
+      });
 
-    it("uses a project key if it exists anywhere in the title", () => {
-      process.env[
-        `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
-      ] = "AB";
-      process.env[
-        `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
-      ] = "true";
-      const regex = getRegex();
-      expect(regex).toEqual(new RegExp(`(.)*(AB-){1}(\\d)+(\\s)+(.)+`));
-      expect(regex.test("other words AB-43 stuff and things")).toBe(true);
+      it("uses a project key and a colon separator if they exist anywhere in the title", () => {
+        process.env[
+          `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB";
+        process.env[
+          `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = ":";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "true";
+        const regex = getRegex();
+        expect(regex.length).toEqual(1);
+        expect(regex[0]).toEqual(new RegExp(`(.)*(AB-){1}(\\d)+(:)+(\\S)+(.)+`));
+        expect(regex[0].test("other words AB-43: stuff and things")).toBe(false);
+        expect(regex[0].test("other words AB-123: PR Title")).toBe(false);
+        expect(regex[0].test("other words AB-43:stuff and things")).toBe(true);
+        expect(regex[0].test("other words AB-123:PR Title")).toBe(true);
+        expect(regex[0].test("AB-43:stuff and things")).toBe(true);
+        expect(regex[0].test("AB-123:PR Title")).toBe(true);
+      });
     });
 
-    it("uses a project key and a colon separator if they exist anywhere in the title", () => {
-      process.env[
-        `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
-      ] = "AB";
-      process.env[
-        `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
-      ] = ":";
-      process.env[
-        `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
-      ] = "true";
-      const regex = getRegex();
-      expect(regex).toEqual(new RegExp(`(.)*(AB-){1}(\\d)+(:)+(\\S)+(.)+`));
-      expect(regex.test("other words AB-43: stuff and things")).toBe(false);
-      expect(regex.test("other words AB-123: PR Title")).toBe(false);
-      expect(regex.test("other words AB-43:stuff and things")).toBe(true);
-      expect(regex.test("other words AB-123:PR Title")).toBe(true);
-      expect(regex.test("AB-43:stuff and things")).toBe(true);
-      expect(regex.test("AB-123:PR Title")).toBe(true);
+    describe("when projectKeys are provided", () => {  
+      it("uses a project key if it exists in projectKeys", () => {
+        process.env[
+          `INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB";
+        const regexes = getRegex();
+        expect(regexes.length).toEqual(1);
+        expect(regexes[0]).toEqual(new RegExp(`(^AB-){1}(\\d)+(\\s)+(.)+`));
+        expect(regexes[0].test("AB-43 stuff and things")).toBe(true);
+      });
+  
+      it("throws an exception if the provided project key is not valid", () => {
+        process.env[
+          `INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "aB";
+        expect(getRegex).toThrow('Project Key  "aB" is invalid');
+      });
+  
+      it("throws an exception if one of the provided project key is not valid", () => {
+        process.env[
+          `INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB\naB\nCD";
+        expect(getRegex).toThrow('Project Key  "aB" is invalid');
+      });
+  
+      it("uses a project key and a colon separator if they exist", () => {
+        process.env[
+          `INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB";
+        process.env[
+          `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = ":";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "false";
+        const regexes = getRegex();
+        expect(regexes.length).toEqual(1);
+        const regex = regexes[0];
+        expect(regex).toEqual(new RegExp(`(^AB-){1}(\\d)+(:)+(\\S)+(.)+`));
+        expect(regex.test("AB-43: stuff and things")).toBe(false);
+        expect(regex.test("AB-123: PR Title")).toBe(false);
+        expect(regex.test("AB-43:stuff and things")).toBe(true);
+        expect(regex.test("AB-123:PR Title")).toBe(true);
+      });
+  
+      it("uses a project key and an underscore separator if they exist", () => {
+        process.env[
+          `INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB";
+        process.env[
+          `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "_";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "false";
+        const regexes = getRegex();
+        expect(regexes.length).toEqual(1);
+        const regex = regexes[0];
+        expect(regex).toEqual(new RegExp(`(^AB-){1}(\\d)+(_)+(\\S)+(.)+`));
+        expect(regex.test("AB-43_stuff and things")).toBe(true);
+        expect(regex.test("AB-123_PR Title")).toBe(true);
+      });
+  
+      it("uses a project key if it exists anywhere in the title", () => {
+        const projectNames: string[] = ["AB", "CD", "EF"];
+        process.env[
+          `INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB\nCD\nEF";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "true";
+        const regexes = getRegex();
+        expect(regexes.length).not.toEqual(1);
+        regexes.forEach((regex: RegExp, index: number) => {
+          expect(regex).toEqual(new RegExp(`(.)*(${projectNames[index]}-){1}(\\d)+(\\s)+(.)+`));
+          expect(regex.test(`other words ${projectNames[index]}-43 stuff and things`)).toBe(true);
+        })
+      });
+  
+      it("uses a project key and a colon separator if they exist anywhere in the title", () => {
+        process.env[
+          `INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB";
+        process.env[
+          `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = ":";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "true";
+        const regexes = getRegex();
+        expect(regexes.length).toEqual(1);
+        const regex = regexes[0];
+        expect(regex).toEqual(new RegExp(`(.)*(AB-){1}(\\d)+(:)+(\\S)+(.)+`));
+        expect(regex.test("other words AB-43: stuff and things")).toBe(false);
+        expect(regex.test("other words AB-123: PR Title")).toBe(false);
+        expect(regex.test("other words AB-43:stuff and things")).toBe(true);
+        expect(regex.test("other words AB-123:PR Title")).toBe(true);
+        expect(regex.test("AB-43:stuff and things")).toBe(true);
+        expect(regex.test("AB-123:PR Title")).toBe(true);
+      });
+  
+      it("uses a project key and a colon separator if they exist", () => {
+        const projectNames: string[] = ["AB", "CD", "EF", "GH"];
+        process.env[
+          `INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB\nCD\nEF\nGH";
+        process.env[
+          `INPUT_${separatorKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = ":";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "false";
+        const regexCollection = getRegex();
+        regexCollection.forEach((regex: RegExp, index: number) => {
+          expect(regex).toEqual(new RegExp(`(^${projectNames[index]}-){1}(\\d)+(:)+(\\S)+(.)+`));
+          expect(regex.test(`${projectNames[index]}-43: stuff and things`)).toBe(false);
+          expect(regex.test(`${projectNames[index]}-123: PR Title`)).toBe(false);
+          expect(regex.test(`${projectNames[index]}-43:stuff and things`)).toBe(true);
+          expect(regex.test(`${projectNames[index]}-123:PR Title`)).toBe(true);
+        })
+      });
     });
+
+    describe("when projectKey and projectKeys both are provided", () => {
+
+      it("gets the default when no project key is provided", () => {
+        process.env[
+          `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "";
+        const regex = getRegex();
+        const defaultRegex =
+          // eslint-disable-next-line no-useless-escape
+          /(?<=^|[a-z]-|[\s\p{Punct}&[^\-]])([A-Z][A-Z0-9_]*-\d+)(?![^\W_])(\s)+(.)+/;
+        expect(regex.length).toEqual(1);
+        expect(regex[0]).toEqual(defaultRegex);
+        expect(regex[0].test("PR-4 this is valid")).toBe(true);
+      });
+
+      it("uses project key if it exists anywhere in the title", () => {
+        const projectNames: string[] = ["AB", "CD", "EF", "GH"];
+        process.env[
+          `INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB\nCD\nEF";
+        process.env[
+          `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "GH";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "true";
+        const regexes = getRegex();
+        expect(regexes.length).not.toEqual(1);
+        regexes.forEach((regex: RegExp, index: number) => {
+          expect(regex).toEqual(new RegExp(`(.)*(${projectNames[index]}-){1}(\\d)+(\\s)+(.)+`));
+          expect(regex.test(`other words ${projectNames[index]}-43 stuff and things`)).toBe(true);
+        })
+      });
+
+      it("multiple project keys are present", () => {
+        const projectNames: string[] = ["AB", "CD"];
+        process.env[
+          `INPUT_${projectKeysInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "AB\n";
+        process.env[
+          `INPUT_${projectKeyInputName.replace(/ /g, "_").toUpperCase()}`
+        ] = "CD";
+        process.env[
+          `INPUT_${keyAnywhereInTitle.replace(/ /g, "_").toUpperCase()}`
+        ] = "true";
+        const regexes = getRegex();
+        expect(regexes.length).not.toEqual(1);
+        regexes.forEach((regex: RegExp, index: number) => {
+          expect(regex).toEqual(new RegExp(`(.)*(${projectNames[index]}-){1}(\\d)+(\\s)+(.)+`));
+          expect(regex.test(`other words ${projectNames[index]}-43 CD-43 stuff and things`)).toBe(true);
+          expect(regex.test(`other words CD-43 ${projectNames[index]}-43 stuff and things`)).toBe(true);
+        })
+      });
+    })
   });
 });
diff --git a/src/main.ts b/src/main.ts
index 8dd0999..fa1fa12 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -5,47 +5,76 @@ export const run = async () => {
   try {
     core.debug("Starting PR Title check for Jira Issue Key");
     const title = getPullRequestTitle();
-    const regex = getRegex();
+    const allPossibleRegex = getRegex();
 
     core.debug(title);
-    core.debug(regex.toString());
+    core.debug(allPossibleRegex.toString());
 
-    if (!regex.test(title)) {
-      core.debug(`Regex ${regex} failed with title ${title}`);
-      core.info("Title Failed");
-      core.setFailed("PullRequest title does not start with a Jira Issue key.");
-      return;
+    for (const regex of allPossibleRegex) {
+      if (regex.test(title)) {
+        core.info("Title Passed");
+        return;
+      }
     }
-    core.info("Title Passed");
+    core.debug(`Regex ${allPossibleRegex} failed with title ${title}`);
+    core.info("Title Failed");
+    core.setFailed("PullRequest title does not start with any Jira Issue key.");
+    return;
     // eslint-disable-next-line  @typescript-eslint/no-explicit-any
   } catch (error: any) {
     core.setFailed(error.message);
   }
 };
-export const getRegex = () => {
-  const projectKey = core.getInput("projectKey", { required: false });
+export const getRegex = (): RegExp[] => {
+  const projectKeyInput = core.getInput("projectKey", { required: false });
+  let projectKeysInput = core.getInput("projectKeys", { required: false });
   const separator = core.getInput("separator", { required: false });
   const keyAnywhereInTitle = core.getBooleanInput("keyAnywhereInTitle", {
     required: false,
   });
 
-  core.debug(`Project Key ${projectKey}`);
+  core.debug(`Project Key ${projectKeyInput}`);
+  core.debug(`Project Keys ${projectKeysInput}`);
   core.debug(`Separator ${separator}`);
   core.debug(`Key Anywhere In Title ${keyAnywhereInTitle}`);
 
-  if (!projectKey || projectKey === "") return getDefaultJiraIssueRegex();
+  if ((!projectKeysInput || projectKeysInput === "") && (!projectKeyInput || projectKeyInput === "")) return [getDefaultJiraIssueRegex()];
 
-  if (!isValidProjectKey(projectKey))
-    throw new Error(`Project Key  "${projectKey}" is invalid`);
+  const projectKeys: string[] = [];
+  // if there is any input in projectKeys.
+  // input separated by multiple lines: split and consume.
+  projectKeysInput = projectKeysInput.trim(); // remove extra spaces.
+  if (projectKeysInput.length > 0) {
+    projectKeysInput.split('\n').forEach((project: string) => {
+      projectKeys.push(project.trim());
+    });
+  }
+  if (projectKeyInput) {
+    projectKeys.push(projectKeyInput);
+  }
 
-  if (!separator || separator === "")
-    return getRegexWithProjectKey(projectKey, keyAnywhereInTitle);
+  projectKeys.forEach((projectName: string) => {
+    if (!isValidProjectKey(projectName))
+      throw new Error(`Project Key  "${projectName}" is invalid`);
+  });
 
-  return getRegexWithProjectKeyAndSeparator(
-    projectKey,
-    separator,
-    keyAnywhereInTitle,
-  );
+  const allPossibleRegex: RegExp[] = [];
+
+  if (!separator || separator === "") {
+    projectKeys.forEach((projectName: string) => {
+      allPossibleRegex.push(getRegexWithProjectKey(projectName, keyAnywhereInTitle));
+    });
+    return allPossibleRegex;
+  }
+
+  projectKeys.forEach((projectName: string) => {
+    allPossibleRegex.push(getRegexWithProjectKeyAndSeparator(
+      projectName,
+      separator,
+      keyAnywhereInTitle,
+    ));
+  });
+  return allPossibleRegex;
 };
 export const getPullRequestTitle = () => {
   const pull_request = github.context.payload.pull_request;