Google has updated the process for setting up AdWords Test Accounts. Test accounts are used by developers to execute AdWords API requests without serving ads or affecting actual account performance.
Starting today, instead of having to complete a web form application for account approval, developers can now create an MCC (master client center) test account from the web UI.
All client accounts set up within the MCC will be test accounts. This is the URL to set up a test MCC account: https://adwords.google.com/um/StartNewMccAccount?testAccount=true. Notice ”?testAccount=true” in the URL; it’s the only noticeable difference from the set-up page for a standard MMC account.
Test accounts have the red “This is a test account” notice as shown in the screenshot below.