Since your users will be redirected to a secure Authorize.Net payment form to fill in their billing information, you may want to customize the look and feel of the payment form to match your website to provide a seamless user experience. In order to customize the Authorize.Net payment form please do the following:
1. Log Into Authorize.Net - https://account.authorize.net/
2. On the first page, look for the “Account” section at the bottom left hand side. Click on “Settings”.
3. On the settings page, the first section is labeled “Transaction Format Settings”. In that section, click on “Payment Form”.
4. In the payment form area, you can customize the header, footer, color settings, and the form fields that appear on the Authorize.Net payment form. To customize each area, just click on the appropriate link.