Please don't test your biller setup with NATS4 Global Access's test account—it won't work correctly.
Setting up on Global Access' Site
Before you can configure Global Access in NATS, you must first sign up for a merchant account with them. Go to Global Access' website, signup for an account, create the join options you intend to use Global Access with, and copy the product codes that are given to you.
Find the password script location and set it to: http://linkdomain/signup/passwd_gaccess.php
After that find the return URL location and set it to: http://linkdomain/signup/returnurl_gaccess.php
When setting your returnurl_gaccess.php path within Global Access' website, you must also append ?key=[KEY] to the end of your URL.
For both examples, simply replace "linkdomain" with the linkdomain to your site.
Setting up Global Access in NATS
To begin setting up Global Access in NATS, go to the Billers Admin. Scroll down to the "Setup New Biller" drop-down menu, select Global Access, and click "Add."
Fill in the Account Number, Username, and Password that you received from Global Access when prompted, and click Save. If you were not provided with the necessary information, please contact Global Access.
Once you have completed the previous steps, go to the Sites Admin, create or edit a tour, and create a new join option.
Set up a join option for each site you wish to configure, and fill in your Global Access product code in the "GACCESS(id:x) Product Code" field (this product code must be obtained directly from Global Access).
Once you have completed these steps, save your join option details. Global Access will not be configured for use as a biller in NATS.