What is Invoice ?
Invoice is (noun) a note sent to ask for payment for services or goods Our invoice dated November 10th has still not been paid. They sent in their invoice six weeks late. Ask the sales assistant to make out an invoice for £250. Synonym bill (verb) to send a note asking for payment for services or goods we invoiced you on November 10th we sent you an invoice on November 10th
source: Easier English, Student Dictionary Upper Intermediate Level