Did you approach the affiliate managers about this?
I agree that faxing is an old technology, but if you’ve got a printer/scanner then you’ll probably be able to print, sign, and submit the invoice by email once you get their prior approval.
Signed invoicing is actually a strong audit control, and we have similar setup with several UK / European organisations (but not all).
I’d rather go through this process with exact amounts specified and paid than all the other rigamarole that you often get with less strict jurisdictions where you get wrong amounts, anonymous descriptions and missing payments.
My accountant is usually pleased to see these invoices during end of year tax time as well.
:hattip: