Invoice Generator — free, no signup

An invoice is a request for payment, and in most countries it is also a tax document. The requirements are broadly consistent: a unique sequential number, the issue date, the full legal name and address of both parties, a clear description of what was supplied, the amount due, and the tax charged shown separately from the net.

The sequential number matters more than people expect. Tax authorities use it to detect gaps, so numbering should be unbroken and never reused — if you void an invoice, issue a credit note rather than reusing its number. INV-0001 upward is fine; what matters is that it never repeats.

If you are VAT registered you must show your VAT number, the rate applied and the tax amount as its own line. A total that silently includes tax is not a valid VAT invoice, and your client cannot reclaim against it. The tax preset here fills the rate and label for 60 countries.

Order of operations matters when a discount is involved: discount comes off the subtotal, then tax applies to what remains. Taxing before discounting overstates the bill and overstates the tax you owe. This builder does it in the correct order and shows you the difference.

Payment terms belong on the document, not in the covering email. State the due date and what happens after it. Net 30 is the common default, but shorter terms get paid sooner, and in the UK and EU you have a statutory right to charge interest on late commercial payments whether or not the invoice mentions it.