What to Include on an Invoice: The Complete Checklist

You have finished the work, the client is happy, and their finance team needs an invoice. A missing purchase order number, a vague line description or no due date is all it takes for that invoice to sit in someone's inbox for a month.

This checklist covers the fields every invoice needs, the extra ones tax rules add when you are VAT registered, the details that make an invoice quick to approve, and a filled-in sample you can copy. If you are new to invoicing altogether, start with how to invoice as a freelancer, then come back here to check the details.

What does every invoice need?#

These fields appear on almost every official list, plus the practical ones that get you paid.

GOV.UK's list for UK businesses asks for a unique identification number, your name, address and contact information, the customer's name and address, a clear description of what you are charging for, the supply date, the invoice date, the amounts charged, VAT if applicable, and the total owed. The UK's Office of the Small Business Commissioner adds the practical ones: a clear "Invoice" title, payment terms and a due date, payment instructions, and the client's PO number if they gave you one.

A few notes on getting each one right:

• Invoice number. Never reuse one. A simple sequence like 001, 002, 003 works; invoice number format compares the common schemes and when each one makes sense.
• Your name. If you work under your own name, that is your business name. Invoicing without a business covers what to put when you have no company.
• Description. Write it for the person in accounts, not your contact. "Website design, 6 days (1 to 31 Oct)" gets approved; "Design work" gets queried.
• Due date. Write an actual date as well as the terms. "Net 30" leaves the reader to do the maths. Net 30 payment terms explains the common options.

Is there a legal format for an invoice?#

There is no single worldwide format. The rules depend on your country and, above all, on whether you are registered for VAT, GST or sales tax.

United Kingdom

Every invoice should carry the details on GOV.UK's list above. Sole traders must also show their name and any business name they use, plus an address where legal documents can be delivered if they trade under a business name. Limited companies must show their full company name as it appears on the certificate of incorporation. If you and your customer are both VAT registered, you must use a VAT invoice, which needs more information (see the next section).

European Union

EU VAT rules set a common list of what a VAT invoice must contain, and each country applies it alongside its own national rules. Your Europe notes that if you are VAT registered, your VAT identification number must appear on all invoices you give to customers. If you are a very small business using your country's VAT exemption, check your national tax office's guidance for any wording it expects.

United States

The IRS does not prescribe an invoice layout. It asks you to keep supporting documents that show the amounts and sources of your income, lists invoices among them, and lets you choose any record-keeping system that clearly shows your income and expenses. If you charge sales tax, your state's rules decide what the invoice must show.

Everywhere else

Countries with a GST or VAT, such as Australia, Canada and India, publish their own "tax invoice" requirements for registered businesses. If that is you, check your template against your tax authority's list.

What extra goes on a VAT invoice?#

Once you are VAT registered, your invoice becomes a tax document your client may use to reclaim VAT, so the list gets longer.

Two UK details catch people out. HMRC says you should normally issue a VAT invoice within 30 days of the tax point (usually the date you supplied the work), and the total VAT must be shown in sterling, which matters if you invoice a client in euros or dollars. For sales of £250 or less, HMRC allows a simpler VAT invoice.

In the EU, a service supplied to a business in another EU country usually goes out without VAT: your client accounts for it in their own country, and your invoice says "reverse charge". Cross-border billing has its own quirks, which invoicing international clients walks through.

What details get an invoice paid faster?#

The legal minimum makes an invoice valid. These extras make it easy to approve.

• The client's PO number. Not every business uses purchase orders, but if your client does, a missing PO number can stop payment. The Small Business Commissioner describes an invoice of more than £12,000 that went unpaid for exactly this reason, until it was reissued with the PO number. Ask for it before you start work.
• The right recipient. The person who hired you often is not the person who pays. Ask whether invoices go to a finance inbox, a named person in accounts payable, or an upload portal.
• The dates you worked. A billing period ("1 to 31 October") or the actual days lets the client check your invoice against their records without emailing you.
• One line per service. Separate design days from a fixed-price logo. Finance teams can approve a clear line faster than a lump sum.
• Payment terms and a date. "Payment due within 14 days, by 14 November 2026."
• Checked payment details. One wrong digit in an account number means a returned payment and a week lost. Asking the client to quote the invoice number as the payment reference makes the payment easy to match.
• A late payment note, if you have agreed one. If your contract allows a late fee or interest, a one-line reminder of it is fine. The rules on what you can charge differ by country.

What should you leave off an invoice?#

Some things cause queries, and some are risky to send at all:

• Sensitive ID numbers. Do not print a Social Security number or national insurance number on an invoice. If a US client needs your taxpayer ID, they will ask for it separately, usually on Form W-9.
• Card numbers or passwords. Payment details mean where to send money, never anything that lets someone take it.
• Charges nobody agreed. A surprise fee is the quickest way to get the whole invoice put on hold. Raise it with your client first.
• Internal shorthand. Ticket numbers and codenames the client's finance team will not recognise.
• The wrong label. A document called "Estimate" or "Quote" is not a request for payment.
• Two currencies. Pick one currency per invoice and say which with an ISO code, such as GBP, USD or EUR.

A signature is optional. None of the official lists above require one, though some clients like to see it.

A sample invoice with every field filled in#

Here is a complete invoice for a UK designer who is not VAT registered, billing one month of day-rate work plus a fixed-price deliverable. Copy the layout and swap in your own details.

INVOICE

From                               Billed to
Sam Rivera                         Northwind Studio Ltd
Brand and web design               Accounts Payable
12 Harbour Road, Bristol           40 King Street, London
sam@example.com                    ap@northwind.example

Invoice number:  SR-2026-014
Invoice date:    31 October 2026
Work period:     1 to 31 October 2026
PO number:       PO-55812
Due date:        14 November 2026

Description                          Qty       Rate      Amount
Website design (day rate)            6 days    £450    £2,700.00
Design system guide (fixed price)    1         £800      £800.00

                                         Subtotal    £3,500.00
                                         Total due   £3,500.00

Payment details
Bank transfer to: Sam Rivera
Sort code: 00-00-00   Account: 12345678
Please use SR-2026-014 as the payment reference.
Payment due within 14 days of the invoice date.

If Sam were VAT registered, the invoice would also need his VAT number, the VAT rate and amount for each line, and the total VAT, and the heading block would show the date of supply if it differed from the invoice date.

How do you make one in Word, Google Docs or a spreadsheet?#

You do not need special software for a correct invoice. A document or spreadsheet works if you set it up once and reuse it.

1. Set up the header

Put "INVOICE" at the top, then two columns: your details on the left, the client's on the right.

2. Add the reference block

Invoice number, invoice date, work period, PO number (if any) and due date, one per line. Finance teams read this block first.

3. Build the line items as a table

Columns for description, quantity, rate and amount. In Google Sheets or Excel, make the amount a formula, such as =B12*C12, so a changed rate updates the total.

4. Add totals, payment details and terms

Subtotal, tax if you charge it, then the total due in bold, followed by your payment details, the reference to use and one line of terms.

5. Save as a PDF and check it

Export to PDF so the layout cannot shift, and check it against the list at the end of this article. Keep a blank copy of the template so next month starts clean.

The weak spot of the manual method is the admin around it: tracking the next number, retyping client details, and remembering which invoices are unpaid.

How BillBee.work fills these in for you#

BillBee.work, a free invoice maker for freelancers, prints most of this checklist automatically once you have added a client and your own details:

• Your details and logo from your profile, and the client's details under "Billed To". If you are VAT registered, add your VAT number to the business details in your profile so it prints with your address.
• Invoice number, invoice date and due date. Numbers follow the format PREFIX-YYYYMM-001, with a prefix you choose for each client.
• Line items with descriptions, days and amounts. Each line can be a day rate, an hourly rate or a fixed price, and you can mix them on one invoice.
• Subtotal, one optional tax line (such as "VAT 20%") and the total, plus the amount in words.
• Payment Details, a free-text block from your profile printed on every invoice: bank details, PayPal or wire instructions, and a one-line terms note such as "Payment due within 14 days by bank transfer".
• An optional signature, and an optional work log: a small calendar of the days you billed, which answers "which days was this for?" before anyone asks.

It is honest to say what it does not do. There is no PO number field, no separate notes or terms field and no custom fields. If a client needs a PO number, put it in the line description (for example "Website design, PO-55812"). Fixed wording you want on every invoice goes in Payment Details. It prints a single tax line, so it does not do split taxes, a VAT breakdown by rate, or a reverse-charge feature; if you need reverse-charge wording, typing it into Payment Details is a workaround, and accounting software is the better fit if most of your invoices need these. On the free plan you share each invoice by link; PDF download is part of Pro.

Your checklist before you send#

Run down this list before every invoice goes out:

1. It says "Invoice" and has a new, unique number.
2. The invoice date and due date are both there, as real dates.
3. Your name, contact details and address are correct.
4. The client's legal or trading name and address are correct, and it is addressed to whoever pays.
5. Each line says what you did, when, how many and at what rate.
6. The PO number is included, if the client uses them.
7. Tax is shown correctly for your registration, or left off if you are not registered.
8. The total is right, in one clearly labelled currency.
9. Your payment details are checked, with the reference you want the client to use.
10. It is saved as a PDF or link and filed with your records.

When it passes, send it to whoever processes payments, as a PDF or a link, and ask them to confirm they have received it.

Create invoices that get you paid faster.

Day rates, hourly or fixed prices, a work log your client can check, and five clean templates. Free to start, no credit card.

Create your first invoice