Authorize.net is the #1 US credit card gateway. You must have an Authorize.net Gateway account and merchant account to accept credit card payments through them.
Activating Authorize.net on your DPD Store
1. Log in to DPD
2. Select the store you would like to activate Authorize.net on and go to Payment Methods
3. Click the "+Add" link for the Authorize.net method
4. Enter your Login ID and Transaction Key from your Authorize.net account
5. Select the cards that you have applied to accept.
Please note, you should only accept cards that you have an agreement for. DPD supports international card types that US based accounts will not support, so don't just click all of them! Additionally, Discover and American Express typically require a separate processing agreement.
6. Finally, check the box to enable the method and click save.