Logo images must be loaded to a Merchant account prior to attempting to use a logo on a payment request - this can be done via API (by any API user or Introducer) or web interface (by authorised Merchant users).
Successfully loading a logo image via API to a Merchant account will return a response displaying a unique ID for the logo image - use this ID in later payment requests.
Any image can be presented as a merchant logo or co-brand logo, neither logo is required for a payment request.
Logo images will automatically be resized down to fit within payment page constraints, but won’t be otherwise altered.