During checkout, a _payment type_ is passed for processing through a [Payment gateway](🔗) to a _payment provider_. Optimizely provides code samples for some common third-party payment providers like PayPal.
The Optimizely Customized Commerce sample site includes these payment methods by default:
Pay by credit card
Pay by phone
Cash on delivery
There are also many other payment providers available, see [Optimizely Add-ons](🔗).
## Pay by credit card
Pay by Credit Card manages payments for major credit card providers. The customer enters credit card details, such as card number, expiration date, card name and Card Verification Value number. The system verifies the information and executes the payment transaction.

## Pay by phone
Pay by Phone manages telephone payments.

## Cash on delivery
Cash on delivery allows customers to pay when picking up the package from a local post office.

## Payment providers available as add-ons
Installation and configuration documentation for payment providers developed by Optimizely for Optimizely Commerce.
[PayPal installation and configuration, 10.5 and higher](🔗)
[DIBS installation and configuration](🔗)
[DataCash installation and configuration](🔗)