Once your shop is up and ready to go, you would want to configure the payment methods and their specifications, so you can bill your customers. Doing that with osCommerce is actually pretty easy once you have created a merchant account with a payment vendor of your choice:
1. Login to the osCommerce Admin Backend
2. Go to Modules section on the left
3. Click on Payments
4. Select your desired payment method from the list
* If you don’t see the needed option there, you can easily create a new one, using the Install Module button on the top left
5. Click the Edit button
6. There are two important options you need to fill: Transaction Mode and Sort Order of Display (lower number equals a higher preference)
7. Hit Update to save your changes
Now you know how you can easily operate your payments.