Apply for credentials by logging in to your Payson Account by clicking ‘My Account’ -> ‘Integration’. Once you have been approved by Payson, you will be notified by email and your credentials will show on the Integration page.
A separate agreement is required to start receiving payments by invoice and at the moment the only supported currency is SEK. The receiver of the payment has to be the same Payson account as the account used for the request, e.g. the email address associated with the Payson account for the PAYSON-SECURITY-USERID used in the HTTP header. Follow this link for more information.