Would it be possible to add an end of month tick box to the contact level payment term settings? Rather than an invoice being due on 30 day terms, this would mark the due date as 30 days after the current month end? (or any other terms a user sets)
It can get tedious working out the days on individual invoices.
Hi there 
Jamie from FreeAgent here, thanks for reaching out.
As this is a main app feature request, I think it would be best placed with our lovely Support team. You can find details on how to contact them here. Through any of the available contact options you will be able to let them know what your feature request is, and the details.
I hope this helps!
Kind regards,
Jamie