There's an extra step you need to take to get Square working in sandbox: you need a Square Developer Dashboard.
What is a Square Developer Dashboard?
A Square Developer Dashboard essentially gives you a “fake” Square seller account, so any transactions you make in your Billforward sandbox environment will also appear in your Square Developer Dashboard. You can verify that all these transactions work in the way you’d expect and that you won’t get any unexpected surprises when you move into your production account.
How do I create a Square Developer Dashboard?
- Visit developer.squareup.com/apps. Sign in with your Square account, or create a new testing account if you like.
Once you're signed in, create an application. This is Square's version of a sandbox environment, and creating it will let your Billforward sandbox environment connect to Square.
- Under Sandbox Test Accounts, click Open on the Default Test Account. This will open a new tab containing your Square Developer Dashboard. Make sure you keep this tab open!
- Sign in to your Billforward sandbox environment in a new tab, and go to Setup > Payment Gateways.
- Click Enable Square and follow the steps. As long as your Square Developer Dashboard is open in another tab, you'll be successfully connected!
And you're done! You can now verify that transactions from your Billforward sandbox will also show up in your Square Developer Dashboard that's open in the other tab.