Free Invoice Generator

How to create an invoice in 3 steps

What to include on an invoice

Every invoice needs an invoice number, your details, your client's details, a description of what was provided, the date, and the total amount due. US businesses don't have a federally mandated format, but the same core fields are still best practice; UK invoices have legal requirements, with extra ones for VAT-registered businesses.

The core fields (every invoice, any country)

A unique invoice number so you and your client can reference it later — sequential formats like INV-1001 make it easy to spot gaps or duplicates. Your business name and contact details (address, email, phone), and your client's name and billing address. The invoice date and, if payment isn't due immediately, a due date. An itemized description of each product or service, with quantity and rate rather than one bundled line — this is the section clients check first, and vague line items are a common reason payment gets delayed while someone asks for clarification. Finally, the total amount due, in a clearly stated currency.

Requirements for US invoices

There's no federal law dictating what a US invoice must contain — the IRS notes that “the law does not require any special kind of records” and that businesses may use any recordkeeping system that clearly shows income and expenses, keeping records for as long as they're needed to support a tax return (IRS — Recordkeeping). In practice, the same core fields above are still expected: they protect you if a client disputes a charge, and they're what your accountant needs at tax time. Some states and industries (e.g. contractors) layer on their own invoicing or licensing requirements, so check local rules if you're unsure.

Legal requirements for UK invoices

Under UK guidance, every invoice must include a unique identification number, your name/company name and address, the customer's name and address, a clear description of the goods or services, the date of supply, the invoice date, the amount(s) charged, and the total amount owed — sole traders must also add the name used to trade and, for legal documents, a delivery address (GOV.UK — invoices: what they must include). If you're VAT-registered, HMRC requires a full VAT invoice for supplies over £250 (including VAT) showing your VAT number and the VAT amount separately, issued within 30 days of the supply. For £250 or less, a simplified VAT invoice is allowed — it only needs your details, the supply date, a description, and the VAT-inclusive total per rate (GOV.UK — VAT record keeping, Notice 700/21).

Optional but useful

A logo for a more professional look, a PO number if your client issued one, payment terms (Net 15, Net 30, or due on receipt) so there's no ambiguity about timing, and bank or payment details so your client can pay without asking how.

Why use an online invoice generator instead of Word or Excel?

A static Word or Excel template asks you to redo work you've already done: duplicating the file, retyping client details you've entered before, and manually checking that every formula still adds up. An online generator removes all three.

Payment delays are already a widespread problem — the Federal Reserve Banks' 2024 Report on Payments found that roughly four out of every five small firms face challenges related to getting paid (Federal Reserve Banks — 2024 Report on Payments). A broken formula, an inconsistent invoice number, or a missing due date is a small mistake that can add days to that wait. In the UK, late payment is common enough that the government sets payment-time rules for its own large suppliers and runs a Small Business Commissioner for small firms in disputes with larger customers. A clear, complete, professional-looking invoice from the start is one of the few things within your control that reduces the odds of ending up in a dispute.

A generator like ZeInvoice also solves the practical annoyances templates create over time: your invoice number increments automatically instead of you tracking the last one used, your totals recalculate live instead of relying on a formula that can silently break when a row is inserted in the wrong place, and every invoice looks consistent because it comes from the same layout rather than a file that's been copy-pasted and tweaked dozens of times. Prefer a file anyway? The free invoice templates download blank in Word, Excel and PDF, including a freelance invoice template.

Need more background first?

If you're not sure yet which document you need or how something on the form works, these guides go deeper than this page does:

• How to make an invoice — a step-by-step walkthrough with examples
• What is an invoice? — the full definition and when you need one
• Invoice vs quote — which one to send, and when
• Invoice vs receipt — requesting payment vs confirming it; once you've been paid, the receipt generator makes the receipt
• Payment terms explained — Due on receipt, Net 15, Net 30, Net 60
• What does Net 30 mean? — the most common payment term, explained
• PDF vs Word vs Excel — which file format to use, and when

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