What to include on an invoice
An invoice is a request for payment, and it is also a record that both sides may need later for accounts or tax. A clear one usually has:
- Your name or business name, address and contact details, plus your tax or registration number if you have one.
- The client's name and address.
- A unique invoice number, and the date you issued it.
- A due date or payment terms, so nobody has to guess when you expect to be paid.
- Each item or service described clearly, with quantity and rate.
- The subtotal, any discount, any tax, and the total that is due.
- How to pay you: bank details, a payment link or another method.
What is legally required differs by country, and by whether you are registered for VAT, GST or sales tax. If you are unsure, ask your accountant or check your tax authority's guidance.
How to number your invoices
Use one running sequence and never reuse a number. INV-0001, INV-0002 and so on is enough. Some people add the year, such as 2026-014, which restarts each January. The generator remembers the highest number you have used and fills in the next one, keeping the same number of digits.
Choosing payment terms
"Due on receipt" means the client should pay straight away. "Net 14" or "14 days" means payment is due 14 days after the invoice date, and "Net 30" means 30. The quick buttons in the generator set the due date from the issue date. Shorter terms usually mean faster payment, but follow whatever you agreed with the client.
How the totals are worked out
Total = subtotal - discount + tax + any extra charge. Tax is calculated on the amount after the discount. Here is a worked example:
| Line | Working | Amount |
|---|---|---|
| Items | 3 x 400.00 | 1,200.00 |
| Discount | 10% of 1,200.00 | -120.00 |
| Taxable amount | 1,200.00 - 120.00 | 1,080.00 |
| Tax | 18% of 1,080.00 | 194.40 |
| Shipping | Added at the end | 25.00 |
| Total | 1,080.00 + 194.40 + 25.00 | 1,299.40 |
Amounts are calculated in whole cents (or the smallest unit of your currency) and rounded to the nearest unit for each figure, so the total on the page always adds up to the lines above it.
Getting paid faster
- Send the invoice as soon as the work is done or agreed.
- Put the payment details on the invoice itself so the client does not need to ask.
- Add a QR code for a payment link if your clients pay from a phone.
- Describe each item clearly enough that the client's accounts team can match it to an order.
- Only add a late fee if you agreed it in advance.
Free, private, and where the limits are
Everything happens in your browser. Your details, client names and amounts are not sent to us, and your saved invoices stay on your device. The trade-off is that they are only there while you keep your browser data, so keep the PDFs that matter. The generator supports one tax rate per invoice, does not send emails or reminders and does not take payments. For a longer walkthrough see how to build a professional invoice. Related tools: barcode generator and resume builder.