Authorize.net payment gateway
Before you can activate Authorize.net as your payment gateway, you must deactivate Shopify Payments or any other credit card gateway you're using.
Deactivate your current payment gateway
To deactivate your current gateway:
From your Shopify admin, click Settings, then click Payments (or press
Click Edit next to your current credit card gateway.
Click Change Gateway to deactivate the gateway.
Click Deactivate in the pop-up to complete deactivation.
Choose Authorize.net as your payment gateway
If you've set up a different payment gateway before setting up Authorize.net, you'll be able to easily reactivate that gateway again by selecting it from the credit card drop-down menu.
To activate Authorize.net as your payment gateway:
Deactivate your current payment gateway if you have one enabled.
Select Authorize.net from the payment gateway drop-down menu.
Once you select Authorize.net, you are prompted to enter your API Login ID and Transaction key to connect Shopify to your Authorize.net account.
When you've entered your credentials, click Activate.
Shopify can connect to Authorize.net only when your Authorize.net is ready to take live transactions, not when you're placing test orders.
When you're ready to leave test mode, you must disable test mode in the Authorize.net merchant interface, as well as disabling it from your Shopify admin.
Disable test mode
Your Authorize.net account will default to a test mode if you've just opened a merchant account with them. The test servers aren't compatible with Shopify, so you must turn off test mode for Authorize.net:
Log into the Merchant Interface at https://secure.authorize.net
Select Settings under Account in the main menu on the left.
Click Test Mode in the Security Settings section.
Click Turn Test OFF to take your account out of Test Mode.