Do you use EIDAS certificates or an equivalent qualified certificate for your communication sessions with your customers?
If you are a European Payment Service Provider (<a href="/glossarycollection/payment-service-provider" style="color:#48277C;" target="_blank" title="Payment Service Provider"><u>PSP</u></a>) you'll need to use Electronic Identification Authentication and Trust Services (<a href="/glossarycollection/electronic-identification%2C-authentication-and-trust-services." style="color:#48277C;" target="_blank" title="Electronic Identification Authentication and Trust Services"><u>EIDAS</u></a>) certificate checking.<br/><br/>
And if you are in the UK you'll need to check Open Banking certificates. The EU are no longer supportingthe issuing of eIDAS certificates to UK registered PSPs.