What is an Invoice?
An invoice is a bill for an account between a buyer and a seller indicating what was sold, and how much is owed. Five thousand years after the Sumerians invented invoices, we’ve added a couple bells and whistles to make record-keeping easy, but that much remains the same.
Invoices are like most bills in that they’re issued from a vendor to a customer for something they’ve already received. But invoices, unlike a restaurant bill, aren’t due immediately upon receiving them. They’re used for account-based transactions between vendors and sellers who work with each other on a regular basis.
Your local takeaway restaurant isn’t likely to set up a credit-based account with you (even if you are a regular customer). But if you’re selling to the same person on a monthly or even weekly basis, it makes sense to set up an account to track.