I’m adding Authorize.NET to one of my client’s CakePHP apps and used the Authorize.NET CakePHP Component which saved me a world of time.
But, after setting everything up, I ran my first transaction and got this error: The merchant login ID or password is invalid or the account is inactive. I double checked my API Login ID and Transaction Key and they were correct. Finally, I stumbled on a helpful thread that set me in the right direction.
I was using the test.authorize.net URL but that is only for developer accounts. Even if you are in Test mode, but have a ‘Normal’ Authorize.NET account, you need to use the secure.authorize.net URL.