What this generator produces
The form above is the whole product. It produces one document: an invoice a client can actually pay from, with the fields a bookkeeper expects to find. On the left you get an ordinary form with real labels; on the right, a running preview and a totals panel that recalculates as you type. When it looks right, Download PDF writes the file locally and your browser saves it.
Because the arithmetic runs on your device, there is no page refresh, no upload queue, and no limit on how many invoices you make. The only thing that needs a network is loading the page itself. Once it is open you can turn your Wi-Fi off and finish the invoice.
- A numbered invoice with issue date and due date, either set by hand or derived from Net 7 to Net 60 terms
- Unlimited line items, each with quantity, unit price, and a per-line amount
- Tax rate you set, applied after discount, with an option to tax shipping
- Discount as a percentage or a flat amount, shipping and other charges, and amount already paid
- Deposit percentage if you bill part payment now and the balance later
- Eighteen currencies, with Japanese yen and other zero-decimal currencies handled correctly
- Notes and payment instructions printed at the bottom of the document
How the totals are calculated
Money is stored as whole minor units - cents, or the smallest unit of the chosen currency - so 0.1 plus 0.2 never becomes 0.30000000000000004. Each line is rounded to the minor unit before it is added to the subtotal, which matches how an accountant reads an invoice: the document must add up exactly as printed, not approximately.
Discount comes off the subtotal first. Tax is then calculated on the discounted amount, and if you switch on taxing shipping, shipping joins that base too. Finally, the total is the discounted subtotal plus tax plus shipping, floored at zero so a large discount cannot produce a negative invoice. The deposit, when used, is a percentage of that total, and the amount shown as due now follows whichever figure you choose to present.
If a row has a unit price but no quantity, it is treated as a single one-off charge rather than zero. That is deliberate: people type a fee as one number, and silently billing zero for an hour of work is the kind of mistake that costs real money.
| Stage | Calculation | Shown as |
|---|---|---|
| Line items | each = round(unit price × qty), summed | Subtotal |
| Discount | percent of subtotal, or flat amount capped at subtotal | Discount |
| Tax | rate × (subtotal − discount + shipping if taxed) | Tax |
| Charges | shipping or other fees added after tax | Shipping |
| Total | subtotal − discount + tax + shipping, minimum zero | Total |
| Deposit | percent of total | Due now |
| Paid | amount already received, subtracted from total | Balance |
Invoice numbering that does not repeat
Duplicate invoice numbers are one of the most common reasons a payment gets rejected by accounts payable, and they happen constantly when people number documents by hand. When you save a draft, the numbers you have used are kept in local storage, and the next invoice is generated from the same pattern with the sequence incremented: INV-2026-09-014 becomes INV-2026-09-015.
The pattern supports a four-digit year, a two-digit year, month, and a sequence with leading zeroes, so you can match whatever your bookkeeping already uses. Nothing syncs between devices - local storage is per browser - so if you run two machines, keep one machine authoritative for numbering, or lock the number field by hand.
What makes an invoice valid, and what this page cannot do for you
A payable invoice needs, at minimum: the word invoice and a unique number, the issue date, a due date or terms, your identity and contact details, the client's identity, a description of what you supplied, the amount, and the currency. Most tax regimes add a registration number and a separately stated tax amount once you are registered, and Australia, South Africa, and several EU countries have named tax-invoice formats with their own rules.
Those rules are jurisdiction-specific and they change. The tool will happily produce a document missing every one of them, because it does not know your country, your registration status, or your industry. Check the requirement with your tax authority or an accountant before you rely on a generated document - and read the field-by-field guide linked below if you are new to billing at all.
Who it is for
Freelancers, contractors, studios, agencies, tradespeople, and small product sellers who bill occasionally rather than continuously. If you send forty invoices a week, you want accounting software with a client database, dunning, and reconciliation - you should not be pasting the same client address from a notes app. If you send four a month and the annoying part is the document itself, this page is the cheaper answer.
It also works when you are the one being asked. A client emails 'can you send me an invoice?' at 4pm and you need a PDF, not a template to fill in later. The specific pages linked below cover the recurring situations where extra fields matter: hourly freelance work, a logo on the header, VAT or GST shown separately, and deposits.