diff --git a/setup-env/README.md b/setup-env/README.md
index 950a259..51b91b9 100644
--- a/setup-env/README.md
+++ b/setup-env/README.md
@@ -2,13 +2,13 @@
 
 This action sets up the following environment variables in the runner environment. These environment variables shall be used in the tests for BrowserStack:
 
-1. `BROWSERSTACK_BUILD_NAME`: This environment variable is set on the basis of the input to `build-name` field. By default, the value will be decided based on the event, i.e. push, pull_request etc for the workflow:
+1. `BROWSERSTACK_BUILD_NAME`: This environment variable is set **only when you pass the `build-name` input**. If you do not pass it, the variable is left unset so that the build name configured in your own test setup (e.g. `browserstack.json` / `browserstack.yml`) is used. Pass the `BUILD_INFO` keyword to get a name generated from the event, i.e. push, pull_request etc for the workflow:
    1. `push` event: `[<Branch-Name>] Commit <commit-sha>: <commit-message> [Workflow: <Workflow-number>]`
    2. `pull_request` event: `[<Branch-Name>] PR <PR-number>: <PR-title> [Workflow: <Workflow-number>]`
    3. `release` event: `[<Branch-Name>] Release <Release-tag>: <Release-name> [Workflow: <Workflow-number>]`
    4. Other events: `<Event-Name> [Workflow: <Workflow-number>]`
 
-2. `BROWSERSTACK_PROJECT_NAME`: This environment variable is set on the basis of the input to `project-name` field. By default, i.e. if any input is not provided, the value will be set as the Repository Name.
+2. `BROWSERSTACK_PROJECT_NAME`: This environment variable is set **only when you pass the `project-name` input**. If you do not pass it, the variable is left unset so that the project name configured in your own test setup is used. Pass the `REPO_NAME` keyword to use the Repository Name.
 3. `BROWSERSTACK_USERNAME`: This environment variable's value is taken from the input to `username` field. Ideal way would be to pass the GitHub Secret as the input, i.e. `username: ${{ secrets.BROWSERSTACK_USERNAME }}`.
 4. `BROWSERSTACK_ACCESS_KEY`: This environment variable's value is taken from the input to `access-key` field. Ideal way would be to pass the GitHub Secret as the input, i.e. `access-key: ${{ secrets.BROWSERSTACK_ACCESS_KEY }}`.
 
@@ -46,10 +46,11 @@ or
     * `build-name: BUILD_INFO - My String at the end`
     * `build-name: String at the Beginning - BUILD_INFO - String at the end`
   * The keyword `BUILD_INFO` will be replaced by the information based on the event of the workflow as described above for `BROWSERSTACK_BUILD_NAME` environment variable.
+  * If you omit this input entirely, `BROWSERSTACK_BUILD_NAME` is **not** exported and your own configured build name is left untouched.
 * `project-name`: (**Optional**)
   * You can pass any string that you want to set as the `BROWSERSTACK_PROJECT_NAME`. E.g. `project-name: My Project Name Goes Here`.
   * You can also pass the keyword `REPO_NAME` as the input. This will set the Repository Name for the `BROWSERSTACK_PROJECT_NAME` environment variable.
-  * If no input is provided, `REPO_NAME` will be considered as the default input.
+  * If you omit this input entirely, `BROWSERSTACK_PROJECT_NAME` is **not** exported and your own configured project name is left untouched.
 
 ---
 **NOTE**
diff --git a/setup-env/dist/index.js b/setup-env/dist/index.js
index 9da6a06..cdd56d3 100644
--- a/setup-env/dist/index.js
+++ b/setup-env/dist/index.js
@@ -34599,6 +34599,10 @@ class ActionInput {
       // non-compulsory fields
       this.buildName = core.getInput(INPUT.BUILD_NAME);
       this.projectName = core.getInput(INPUT.PROJECT_NAME);
+
+      // Capture before _validateInput() replaces blanks with generated defaults.
+      this.buildNameProvided = Boolean(this.buildName && this.buildName.trim());
+      this.projectNameProvided = Boolean(this.projectName && this.projectName.trim());
       this.githubApp = core.getInput(INPUT.GITHUB_APP);
       this.githubToken = core.getInput(INPUT.GITHUB_TOKEN);
       this.rerunAttempt = process?.env?.GITHUB_RUN_ATTEMPT;
@@ -34632,13 +34636,23 @@ class ActionInput {
     core.exportVariable(ENV_VARS.BROWSERSTACK_ACCESS_KEY, this.accessKey);
     core.info(`Use ${ENV_VARS.BROWSERSTACK_ACCESS_KEY} environment variable for your access key in your tests\n`);
 
-    core.exportVariable(ENV_VARS.BROWSERSTACK_PROJECT_NAME, this.projectName);
-    core.info(`${ENV_VARS.BROWSERSTACK_PROJECT_NAME} environment variable set as: ${this.projectName}`);
-    core.info(`Use ${ENV_VARS.BROWSERSTACK_PROJECT_NAME} environment variable for your project name capability in your tests\n`);
+    // Export only when supplied: an env var outranks the user's browserstack.json,
+    // so a generated default would silently replace it. BUILD_INFO / REPO_NAME opt in.
+    if (this.projectNameProvided) {
+      core.exportVariable(ENV_VARS.BROWSERSTACK_PROJECT_NAME, this.projectName);
+      core.info(`${ENV_VARS.BROWSERSTACK_PROJECT_NAME} environment variable set as: ${this.projectName}`);
+      core.info(`Use ${ENV_VARS.BROWSERSTACK_PROJECT_NAME} environment variable for your project name capability in your tests\n`);
+    } else {
+      core.info(`No project-name input given, so ${ENV_VARS.BROWSERSTACK_PROJECT_NAME} was left unset and your own configuration will be used. Pass project-name (or the REPO_NAME token) to set it here.\n`);
+    }
 
-    core.exportVariable(ENV_VARS.BROWSERSTACK_BUILD_NAME, this.buildName);
-    core.info(`${ENV_VARS.BROWSERSTACK_BUILD_NAME} environment variable set as: ${this.buildName}`);
-    core.info(`Use ${ENV_VARS.BROWSERSTACK_BUILD_NAME} environment variable for your build name capability in your tests\n`);
+    if (this.buildNameProvided) {
+      core.exportVariable(ENV_VARS.BROWSERSTACK_BUILD_NAME, this.buildName);
+      core.info(`${ENV_VARS.BROWSERSTACK_BUILD_NAME} environment variable set as: ${this.buildName}`);
+      core.info(`Use ${ENV_VARS.BROWSERSTACK_BUILD_NAME} environment variable for your build name capability in your tests\n`);
+    } else {
+      core.info(`No build-name input given, so ${ENV_VARS.BROWSERSTACK_BUILD_NAME} was left unset and your own configuration will be used. Pass build-name (or the BUILD_INFO token) to set it here.\n`);
+    }
 
     if (await this.checkIfBStackReRun()) {
       await this.setBStackRerunEnvVars();
diff --git a/setup-env/src/actionInput/index.js b/setup-env/src/actionInput/index.js
index 95597c5..11c8c0c 100644
--- a/setup-env/src/actionInput/index.js
+++ b/setup-env/src/actionInput/index.js
@@ -32,6 +32,10 @@ class ActionInput {
       // non-compulsory fields
       this.buildName = core.getInput(INPUT.BUILD_NAME);
       this.projectName = core.getInput(INPUT.PROJECT_NAME);
+
+      // Capture before _validateInput() replaces blanks with generated defaults.
+      this.buildNameProvided = Boolean(this.buildName && this.buildName.trim());
+      this.projectNameProvided = Boolean(this.projectName && this.projectName.trim());
       this.githubApp = core.getInput(INPUT.GITHUB_APP);
       this.githubToken = core.getInput(INPUT.GITHUB_TOKEN);
       this.rerunAttempt = process?.env?.GITHUB_RUN_ATTEMPT;
@@ -65,13 +69,23 @@ class ActionInput {
     core.exportVariable(ENV_VARS.BROWSERSTACK_ACCESS_KEY, this.accessKey);
     core.info(`Use ${ENV_VARS.BROWSERSTACK_ACCESS_KEY} environment variable for your access key in your tests\n`);
 
-    core.exportVariable(ENV_VARS.BROWSERSTACK_PROJECT_NAME, this.projectName);
-    core.info(`${ENV_VARS.BROWSERSTACK_PROJECT_NAME} environment variable set as: ${this.projectName}`);
-    core.info(`Use ${ENV_VARS.BROWSERSTACK_PROJECT_NAME} environment variable for your project name capability in your tests\n`);
+    // Export only when supplied: an env var outranks the user's browserstack.json,
+    // so a generated default would silently replace it. BUILD_INFO / REPO_NAME opt in.
+    if (this.projectNameProvided) {
+      core.exportVariable(ENV_VARS.BROWSERSTACK_PROJECT_NAME, this.projectName);
+      core.info(`${ENV_VARS.BROWSERSTACK_PROJECT_NAME} environment variable set as: ${this.projectName}`);
+      core.info(`Use ${ENV_VARS.BROWSERSTACK_PROJECT_NAME} environment variable for your project name capability in your tests\n`);
+    } else {
+      core.info(`No project-name input given, so ${ENV_VARS.BROWSERSTACK_PROJECT_NAME} was left unset and your own configuration will be used. Pass project-name (or the REPO_NAME token) to set it here.\n`);
+    }
 
-    core.exportVariable(ENV_VARS.BROWSERSTACK_BUILD_NAME, this.buildName);
-    core.info(`${ENV_VARS.BROWSERSTACK_BUILD_NAME} environment variable set as: ${this.buildName}`);
-    core.info(`Use ${ENV_VARS.BROWSERSTACK_BUILD_NAME} environment variable for your build name capability in your tests\n`);
+    if (this.buildNameProvided) {
+      core.exportVariable(ENV_VARS.BROWSERSTACK_BUILD_NAME, this.buildName);
+      core.info(`${ENV_VARS.BROWSERSTACK_BUILD_NAME} environment variable set as: ${this.buildName}`);
+      core.info(`Use ${ENV_VARS.BROWSERSTACK_BUILD_NAME} environment variable for your build name capability in your tests\n`);
+    } else {
+      core.info(`No build-name input given, so ${ENV_VARS.BROWSERSTACK_BUILD_NAME} was left unset and your own configuration will be used. Pass build-name (or the BUILD_INFO token) to set it here.\n`);
+    }
 
     if (await this.checkIfBStackReRun()) {
       await this.setBStackRerunEnvVars();
diff --git a/setup-env/test/actionInput/index.test.js b/setup-env/test/actionInput/index.test.js
index 34460b1..bfab23a 100644
--- a/setup-env/test/actionInput/index.test.js
+++ b/setup-env/test/actionInput/index.test.js
@@ -48,6 +48,36 @@ describe('Action Input operations for fetching all inputs, triggering validation
       expect(actionInput.projectName).to.eq('validatedProjectName');
     });
 
+    it('Records that build-name and project-name were supplied', () => {
+      stubbedInput.withArgs(INPUT.BUILD_NAME).returns('someBuildName');
+      stubbedInput.withArgs(INPUT.PROJECT_NAME).returns('someProjectName');
+      const actionInput = new ActionInput();
+      // eslint-disable-next-line no-unused-expressions
+      expect(actionInput.buildNameProvided).to.be.true;
+      // eslint-disable-next-line no-unused-expressions
+      expect(actionInput.projectNameProvided).to.be.true;
+    });
+
+    it('Records that build-name and project-name were NOT supplied when absent', () => {
+      stubbedInput.withArgs(INPUT.BUILD_NAME).returns('');
+      stubbedInput.withArgs(INPUT.PROJECT_NAME).returns('');
+      const actionInput = new ActionInput();
+      // eslint-disable-next-line no-unused-expressions
+      expect(actionInput.buildNameProvided).to.be.false;
+      // eslint-disable-next-line no-unused-expressions
+      expect(actionInput.projectNameProvided).to.be.false;
+    });
+
+    it('Treats a whitespace-only name input as not supplied', () => {
+      stubbedInput.withArgs(INPUT.BUILD_NAME).returns('   ');
+      stubbedInput.withArgs(INPUT.PROJECT_NAME).returns('\t ');
+      const actionInput = new ActionInput();
+      // eslint-disable-next-line no-unused-expressions
+      expect(actionInput.buildNameProvided).to.be.false;
+      // eslint-disable-next-line no-unused-expressions
+      expect(actionInput.projectNameProvided).to.be.false;
+    });
+
     it('Takes input and throws error if username is not provided in input', () => {
       stubbedInput.withArgs(INPUT.USERNAME, { required: true }).throws(Error('Username Required'));
       try {
@@ -94,6 +124,9 @@ describe('Action Input operations for fetching all inputs, triggering validation
       actionInput.accessKey = 'someAccessKey';
       actionInput.buildName = 'someBuildName';
       actionInput.projectName = 'someProjectName';
+      // _fetchAllInput is stubbed out above, so these flags have to be set by hand.
+      actionInput.buildNameProvided = true;
+      actionInput.projectNameProvided = true;
 
       // Stub checkIfBStackReRun to return true
       sinon.stub(actionInput, 'checkIfBStackReRun').returns(Promise.resolve(true));
@@ -111,6 +144,39 @@ describe('Action Input operations for fetching all inputs, triggering validation
       sinon.assert.calledWith(core.exportVariable, ENV_VARS.BROWSERSTACK_BUILD_NAME, 'someBuildName');
     });
 
+    it('Does not export BROWSERSTACK_PROJECT_NAME when no project-name input was given', () => {
+      actionInput.projectNameProvided = false;
+      actionInput.setEnvVariables();
+      sinon.assert.neverCalledWith(
+        core.exportVariable, ENV_VARS.BROWSERSTACK_PROJECT_NAME, sinon.match.any,
+      );
+      // the other variables are unaffected
+      sinon.assert.calledWith(core.exportVariable, ENV_VARS.BROWSERSTACK_BUILD_NAME, 'someBuildName');
+      sinon.assert.calledWith(core.exportVariable, ENV_VARS.BROWSERSTACK_USERNAME, 'someUsername');
+    });
+
+    it('Does not export BROWSERSTACK_BUILD_NAME when no build-name input was given', () => {
+      actionInput.buildNameProvided = false;
+      actionInput.setEnvVariables();
+      sinon.assert.neverCalledWith(
+        core.exportVariable, ENV_VARS.BROWSERSTACK_BUILD_NAME, sinon.match.any,
+      );
+      sinon.assert.calledWith(core.exportVariable, ENV_VARS.BROWSERSTACK_PROJECT_NAME, 'someProjectName');
+      sinon.assert.calledWith(core.exportVariable, ENV_VARS.BROWSERSTACK_ACCESS_KEY, 'someAccessKey');
+    });
+
+    it('Exports neither name when neither input was given, leaving the user config to win', () => {
+      actionInput.buildNameProvided = false;
+      actionInput.projectNameProvided = false;
+      actionInput.setEnvVariables();
+      sinon.assert.neverCalledWith(
+        core.exportVariable, ENV_VARS.BROWSERSTACK_BUILD_NAME, sinon.match.any,
+      );
+      sinon.assert.neverCalledWith(
+        core.exportVariable, ENV_VARS.BROWSERSTACK_PROJECT_NAME, sinon.match.any,
+      );
+    });
+
     it('Calls setBStackRerunEnvVars when checkIfBStackReRun returns true', async () => {
       const setBStackRerunEnvVarsStub = sinon.stub(actionInput, 'setBStackRerunEnvVars').resolves();
       await actionInput.setEnvVariables();