To allow buyers to place an order or make a purchase online without paying by credit card. You define the custom payment by providing instructions for how you want the buyer to submit payment for their purchase outside of the software.
Offering custom payments (eg pay by check) requires someone on your team to manually record the payment against the online order and email a receipt once payment has been received.
To define your custom payment instructions:
Go to Admin > Site Settings > Payment/Credit Card > Custom Payment Instructions (access requires chair role)