Configure Multiple Projects Access in GCP

Sign in to your GCP console.

Click on the project drop-down menu in the top navigation bar and select New Project or you can either create a new Project or use an existing project with service Account.

Enter a name for your new project. Choose the organization that own the new project or select No organization if you do not have one.

Click on the Create button to create the new project.

You can repeat the step 2 to 4 to create as many projects as you need.

To link multiple projects in a single service account, navigate to IAM & Admin page and choose Service Account.

Click on the Create Service Account button. Follow the prompts to create the service account and grant it the necessary permissions.

You can either use an existing service account or create a new service account.

From the Keys tab, click Add Key to generate a private key in JSON file.

Go to the IAM & Admin page in the GCP console and select IAM.

You have to first change the project before you click on IAM & Admin and then try to grant privilege.

Click on the Grant access button to add a new project.

In the New principals field, enter the email address of the service account you want to link to the project.

Click on the Save button to associate the service account to your project.

Repeat these steps for each project that you want to link to your original project. You can manage the service account permissions by going to the IAM & Admin page in the GCP console and selecting IAM for each project.

Make sure that the Service Account has permissions to least common ancestor (common ancestor to all the projects selected) resource level, such as a folder or organization.