To initiate a payment using a single payment form, you need to direct the user to a special URL and pass several required parameters for the payment.


public_key – Public key, which can be obtained in the project settings.
sum – Payment amount
desc – Order description. Used only for information purposes when making a payment.
paySystem – Optional parameter that specifies which payment system to redirect the user to immediately without showing the selection page. Possible values: visa, mastercard, litecoin, xrp, dot, solana, bitcoin

Receipt Data

After payment initiation, the user is redirected to a receipt page where the payment status is tracked. Upon receiving either a successful or error status, the user is redirected to the partners website (Fail URL/Success URL fields in the personal account settings) with GET parameters:

account – Subscriber ID in the partners system provided during payment
paymentId – Payment number in Pay4Bit system

Digital Signature of the Request

As an additional security measure for your payments, we have created a digital signature system for requests. The presence of a signature ensures protection against tampering with transmitted values (e.g., changing the payment amount or order number).

sign – MD5 hash. The result of concatenating the parameters: account, currency, desc, sum, and the projects secret key (see the "settings" section on the project page in the personal account).