Invoices and payment by business client?

basic

6 Jul 2015 at 19:00 · Viewed 1525 times

I do project based work for a UK business as a French registered auto-entrepreneur business.

When do I have to write my invoice, the day I finish the work? I do projects for several days and then typically wait to see if there is more follow-up work for the same project. Is it okay to wait? When does an invoice become a facture périodique ou récapitulative?
I believe I have to include the mentions obligatoires regarding late payment if I am billing a company (even abroad?).
1. Do I have to charge the late fines? In a previous post from several years ago, you said no.
2. The deadlines can vary (up to 60 days, end of the month after 45 days (?), or 45 for factures périodiques ou récapitulatives), but I don’t understand what the deadline actually refers to. The day the company paying me wires the money or the day the money arrives in my account?
What are the current late payment fees? If I understand it correctly, you can either do a complicated calculation, or charge 2.97%.

Answered