What to include on an invoice

The document must say what it is. "Invoice" at the top, in the largest type on the page, tells a finance team to route it to accounts payable rather than to file it as a quote or a statement. If the document is something else — a pro forma invoice, a credit note, a receipt — the title must say so, because those documents are treated differently.

In Simple Invoice the title is a setting on the header block, so the same layout can produce an invoice, a pro forma or a quote by changing one field. Invoice vs receipt vs quote explains when each is the right document.

Every invoice carries a number that no other invoice from you has. Tax authorities generally expect the sequence to be continuous, clients use it to reference the payment, and you use it to find the document later. A prefix plus a padded counter — INV-0042 — is enough; adding the year (INV-2026-0042) helps when you file by year. Invoice numbering best practices covers the trade-offs.

The number belongs in two places: prominently near the title, and in the details list so it is unambiguous. Simple Invoice can show it in the header block and always lists it in the details block; the counter increments each time you create an invoice and warns you if a number is already in use.

The issue date fixes the invoice in time — for your books, for the client's accounting period and for calculating when payment is due. The due date is the date by which payment must arrive; state it as a calendar date, not only as a term like "30 days", so nobody has to count.

Some invoices also need a supply date or tax point — the date the goods were delivered or the service completed — when it differs from the issue date. Add it in a reference field or a text block if your jurisdiction asks for it.

Write dates in a format the client cannot misread. 12/09/2026 means different things in different countries; 12 September 2026 or 2026-09-12 does not. Simple Invoice formats dates from a pattern you choose, in any of twenty-five locales, so a French client can receive 12 septembre 2026 without you typing it.

Name, address and a way to contact you at minimum. If you are registered for VAT, GST or a similar tax, the registration number is normally mandatory. Sole traders in some countries must show their own name alongside the trading name, and companies often must show their registration number and registered office.

This is the From block. Fill it once in your business profile; Simple Invoice snapshots it onto every invoice, so old invoices keep the details that were correct when they were issued.

The Bill To block names who owes the money. Use the legal entity that contracted you, with its address and — where tax rules demand it, for example on business-to-business sales across borders — its tax registration number. If the client gave you a contact name, department or cost centre for the invoice, include it; accounts payable teams route by these fields.

Type these details into the Bill To block on the invoice. Extra fields (a cost centre, a supplier number they assigned to you) print when the block's extra-fields toggle is on.

Each line describes one deliverable specifically enough that the person approving payment can match it to an order, quote or contract. Include the period for time-based work ("Consulting — August 2026"), the deliverable for project work ("Logo system — final files") and the product name and variant for goods.

The items block carries one row per line. A secondary details line under each description is the right place for scope notes, dates worked or a ticket reference, so the main description stays short enough to scan.

For every line: how many, of what unit, at what rate, and the resulting amount. For a fixed-price deliverable the quantity is one and the rate is the price. Showing the arithmetic lets the client verify the total without asking, and it is what tax authorities mean when they require the unit price and quantity.

Simple Invoice shows columns for number, unit, quantity, rate, tax, discount and amount; hide the ones a given invoice does not need. Line amounts are quantity times rate, rounded to the currency's decimals, with any per-line discount applied and shown.

The totals block moves from the sum of the lines to the figure the client must pay: subtotal, any invoice-level discount, each tax shown separately with its label and rate, the total, any amount already paid, and the balance due. Where you charge tax, the tax amount and the rate applied must appear; where a line is exempt or zero-rated, the invoice should say so. Tax basics for invoices explains the vocabulary.

Make the balance due the most visible number on the page. Simple Invoice emphasises it by default, and shows amount paid and balance due whenever a deposit has been recorded.

State the currency once, unambiguously. A bare $ could be US, Canadian, Australian or several others; the ISO code — USD, CAD, AUD — is never ambiguous, so use it at least once, for example next to the total or in the payment terms.

Simple Invoice formats every amount from an ISO currency code and lets you display the symbol, the code or both, with separators and decimals matched to the client's locale. How to invoice international clients covers choosing and presenting a currency.

Payment details are the part clients most often have to ask for. Give every identifier their bank will request, exactly as your bank records it.

State the due period in plain language and the consequences of missing it, if you apply any. "Payment due within 14 days of the invoice date. Late payments may incur interest as permitted by law." is complete; "Net 14" assumes the reader knows the shorthand. If you offer an early-payment discount or require a deposit, those terms belong here too. Invoice payment terms explained has wording you can adapt.

The terms block prints your default terms text; edit it per invoice when a client negotiated something different.

None of these are universally required, and each one removes a reason for a client to write back instead of paying.

Do not include more personal data than the client needs — your date of birth or a personal identity number rarely belongs on an invoice unless your tax authority requires it. Do not include full card numbers, passwords for a client portal, or internal cost breakdowns you would not want forwarded. Keep marketing to a single line at most; the invoice's job is to be paid, not to sell the next project.

Run down this list before every send. It takes less time than one follow-up email.