As a UK business we offer clients 30 days to pay their invoices with us, like most b2b companies do.
Would be good if we could specify the payment days, possibly in the client themselves to allow for different terms. There could even be a default setting in the invoice configuration new clients would inherit?
This way when we added a new invoice on a client it would use this to calculate the correct due date as opposed to us having to amend it manually every time.
Just a simple amend that would make things more watertight, it's so easy to forget to do after creating an invoice and the embarrassment of whmcs sending overdue reminders after an invoice has only recently been sent is avoidable!