How to invoice for work you have already been paid for

Send a receipt, not an invoice — an invoice asks for money that has already arrived and confuses everyone's books.

If the money landed first — a deposit, a cash job, a card payment on the day — the document you owe the client is a receipt: proof they paid. Sending an invoice marked paid works too, provided it is clearly marked, but sending a plain invoice after payment is how a client ends up paying twice and how your own records end up double-counting income.

Both documents still need a number and a date, because both are records for tax purposes.

The core distinction

An invoice is a request: here is what you owe and when it is due. A receipt is a confirmation: this amount has been paid. One creates a debt, the other discharges it. They are frequently the same information at two points in time.

When each is required

Business customers usually need the invoice, because that is what enters their accounts payable and supports a tax claim. Consumers usually want the receipt, because they have already paid and want proof.

Where cash is involved, several countries require a receipt specifically — and in a few, receipts must come from a registered system or book rather than being written out. Retail in the Philippines and Kenya are examples where the form of the document is prescribed.

When you need both

Most straightforwardly: work done on terms. You invoice on completion, the customer pays three weeks later, and a receipt confirms the payment arrived. For business customers the bank record usually does that job informally, but for consumers — especially paying cash — issue the receipt. It protects you as much as them, because it evidences the date money changed hands.

What a receipt should show

• That it is a receipt, not an invoice.
• The date payment was received, which may not be the invoice date.
• The amount received, and the method.
• A reference to the invoice it settles.
• Your business details, and your tax number if registered.

The invoice reference matters most. A receipt for £3,708 with nothing tying it to invoice 1043 is a document neither of you can reconcile in a year.

Part payments

Issue a receipt for what was actually received and state the balance remaining. "Received £1,200 against invoice 1043; balance £2,508 due 14 October" is one line and it prevents the most common misunderstanding in part-paid work — the customer believing the matter is closed. Accepting part payment covers the rest.

Neither is a proforma

A proforma comes before both: it proposes what will be supplied and what it will cost, creates no debt and no tax point. Three documents, three stages. Proforma invoices covers when that first stage is useful.

Both are records you must keep

Retention rules cover receipts as well as invoices, for the same period. Where you paid someone else, their receipt is your evidence of the expense — which is the half of this people lose. A drawer of faded till receipts is a genuinely poor system, and photographing them as they arrive is a much better one.

EstimateBill tracks what is unpaid, reminds you on the due date, and writes the follow-up message for you in three tones. See how the reminders work.