Files can be attached to payment requests without context, within a custom field or within a product field.
- Only PDF files under 5mb are accepted
- A maximum of 3 files able to be attached without context
- Uploading a file to a payment request can only be done once the payment request is created, as a separate API request
- Files can only be attached to a payment request before the payment request is accepted/completed (the exception to this is when a product field is configured to allow updates after the payment request has been accepted)
- Files can be retrieved from any payment request in any status