First you send a PROPER NOTICE. When they indicate that they want to do business with you (accept your contract) by agreeing to your terms, then you can send an invoice and you're off to the races a la Pete Daoust. You can't send an invoice to someone who refuses to contract with you. < As far as I understand.
Printed copy · Anthology Volume 3, page 290Printed copy from The Tender For Law Anthology, Volume 3, page 290 (printed 13 June 2014). Added by this site; not part of the Facebook export.