🧾 Invoice Generator

What an invoice has to contain, and why the numbering matters

An invoice is a legal document, not a letter asking for money. Most tax authorities require the same core set of information, and leaving out one item can make the invoice unusable for the client's own tax deduction — which is how a missing tax number turns into a payment delay.

• A unique, sequential number. Gaps and duplicates are the thing inspectors look for first.
• The issue date, and the supply date if it differs.
• Your full legal name, address and tax identification number.
• The client's name, address and tax number where required, which for cross-border business usually means always.
• A clear description of what was supplied, with quantities and unit prices.
• The net amount, the tax rate and amount, and the total.
• Payment terms and bank details.

This generator produces a clean document with all of the above. It is a template rather than a compliance product: the exact requirements vary by country and by what you sell, and some jurisdictions now require invoices to be issued through certified software that reports to the tax authority.

Sequential numbering

The requirement is that numbers run in an unbroken sequence within a series, so that a missing invoice is visible. 2026-001, 2026-002 and so on works, and so does resetting each year as long as the series is identifiable. What does not work is numbering by date alone, or skipping a number because an invoice was cancelled — a cancelled invoice stays in the sequence and is corrected with a credit note, not deleted.

If you need separate series, for example for different business lines, use a prefix: A-2026-001 and B-2026-001. Each series must be internally unbroken; they do not need to be unbroken with each other.

Several countries are moving to mandatory structured e-invoicing, where the invoice must be issued in a machine-readable format and sometimes reported to the tax authority in real time. Spain's Verifactu and Italy's SdI are examples, and the EU has an agreed direction of travel. A printed PDF may not be enough for business-to-business invoicing in your country — check before relying on one.

Withholding, and why your total can be lower than the tax

In some countries a self-employed person must show a withholding deduction on the invoice: the client pays part of the invoice to the tax authority on your behalf rather than to you. Spain's IRPF retention works this way, commonly at 15% or 7% for new freelancers. The invoice still shows the full net amount and the full tax, with the withholding subtracted at the bottom.

Total due = net + tax − withholding

The money withheld is not lost: it is an advance payment against your own annual tax bill. But it does mean your cash receipt is lower than the invoice headline, which matters for planning — see the budget calculator if that gap is new to you.

Payment terms actually change when you get paid

Net 30 is the common default and is worth questioning for a small supplier, because it means financing your client for a month. Late payment legislation in the EU and the UK sets a default limit of 30 days where no term is agreed and entitles you to interest and a fixed recovery charge on late payments, which many small suppliers never claim.

Nothing here leaves your browser

The invoice is built and printed locally. There is no account, no upload and no server copy, which also means there is no stored history — save the PDF yourself. That is a deliberate trade: most free invoice services are free because they keep your client list. For checking the bank details you put on it, the IBAN validator runs locally too.

A worked example

Ten hours of consulting at €60 and one maintenance item at €120 gives a net of €720. At 21% VAT the tax is €151.20 and the total €871.20. If a 15% withholding applies, €108 is deducted and the client transfers €763.20, paying the €108 to the tax authority against your account. The invoice still shows €720 of income and €151.20 of VAT collected, and both figures go into your own returns unchanged.

Most people arrive here on the way to something else, so it is worth knowing the iban validator, which handles the next part, and the VAT calculator, which covers the case just beyond.

Frequently Asked Questions (FAQs)