What to Include on an Invoice: 2026 Checklist and Common Mistakes

What to include on an invoice: the word “Invoice”, your business name and contact details, the customer's name and address, a unique invoice number, the issue date and due date, an itemized list with quantities and prices, subtotal, discounts, tax, shipping, the total due and payment instructions. VAT-registered sellers usually also need their VAT number and the tax rate per line.

Those are the 12 or so fields that let a customer pay without emailing you a question, and let you or your accountant find the invoice later. Below is the full checklist as a table, the extra fields sales tax and VAT can require, how to word late fees, and the mistakes that most often delay payment. If you just need the invoice made, our free invoice generator has a field for each item on this list and downloads a PDF. For the full walkthrough with numbering and worked examples, see how to make an invoice for a small business. This is general information, not tax or legal advice.

What to include on an invoice: the checklist

Run through this table before you send any invoice. The first ten rows apply to nearly every business; the rest depend on what you sell and where.

Invoice field requirements were checked in October 2026. Marketplaces change their rules, so confirm the current requirements in your seller dashboard before you upload a large batch.

What makes an invoice legally valid?

In the US there's no single federal invoice format; an invoice that clearly identifies both parties, what was sold, the amount and the date is generally fine, and you must keep records that support your income. VAT countries are stricter, because a VAT invoice lets the buyer reclaim tax.

Rules change and have thresholds and exceptions (simplified invoices for small amounts, reverse charge for cross-border business sales, and so on), so treat this table as a starting point and check your tax authority's page or ask an accountant.

How do I show sales tax or VAT on an invoice?

Add tax after discounts, show the rate and the amount on its own line, and give your tax number if you're registered. If you charge more than one rate, show a line for each.

• US sales tax: rates depend on the state and often the city or county. Only add it if you are required to collect it. On marketplace orders (Etsy, Amazon, eBay and others), the marketplace usually collects and remits sales tax for you in most states, so don't add it again.
• Tax-exempt buyers: wholesale buyers with a resale certificate, and some nonprofits, may be exempt. Write “Sales tax exempt, resale certificate on file” and keep the certificate.
• VAT: show the net amount, the VAT rate, the VAT amount and the gross total. Example: “Net £200.00, VAT 20% £40.00, Total £240.00”.
• Not registered for VAT: don't show VAT or call it a VAT invoice. Some sellers add “Not VAT registered” to avoid questions.

Should I include late fees on an invoice?

Include a late fee only if the customer agreed to it before the work or order, for example in your quote, contract or wholesale terms; adding one for the first time on the invoice is hard to enforce. Keep it specific and lawful.

• State the trigger and amount: “A late fee of 1.5% per month applies to balances unpaid after the due date.”
• Check limits: in the US, the maximum interest or late fee depends on your state. In the UK, businesses can usually claim statutory interest on late payments from other businesses.
• Offer a carrot too: an early-payment discount such as “2/10 Net 30” (2% off if paid within 10 days) often works better than a penalty.
• Be careful with consumers: consumer protection rules on fees are usually stricter than for business customers.

What are the most common invoice mistakes?

Most late payments trace back to an invoice that made the customer stop and ask something.

What should go in the invoice notes?

Keep notes short and useful: anything the customer needs to act on or keep. Good examples:

• “Please include invoice number INV-2026-014 as your payment reference.”
• “Returns accepted within 30 days of delivery; see yourstore.com/returns.”
• “Deposit of $150 received October 1, 2026, deducted above.”
• “Thank you for your order. Questions? Reply to this email.”

If you ship physical goods, you don't need to print the invoice and put it in the box. Many sellers email the invoice and include a packing slip, which lists the items without prices. Our packing slip generator makes one from the same details, and what is a packing slip explains when to use each. Your SKU numbers belong on both.

Invoice checklist before you hit send

1. Invoice number is new and follows the last one.
2. Customer name and billing address are correct (and the PO number, if they use them).
3. Every line has a clear description, quantity and price.
4. Discounts, tax and shipping are shown separately and the math adds up.
5. Due date is written as a date.
6. Payment methods and details are on the invoice.
7. Your tax or VAT number is included if you're registered.
8. It's saved as a PDF and a copy is filed.

Frequently asked questions

What are the basic requirements of an invoice?

Your business details, the customer's details, a unique invoice number, the issue date, a description of what was sold with quantities and prices, the total amount due and the payment terms. VAT-registered businesses usually need extra details such as their VAT number and the tax per rate.

Does an invoice need a due date?

It isn't always legally required, but it should have one. A written due date, such as November 10, 2026, removes any argument about when payment becomes late and is the easiest way to get paid on time.

Do I need to put my address on an invoice?

Generally yes. Business customers use your name and address to match the invoice to a supplier, and VAT invoices require it. Home-based sellers sometimes use a PO box or registered business address instead, where local rules allow.

Is an invoice the same as a receipt?

No. An invoice asks for payment and a receipt confirms payment was made. If a customer has already paid, you can mark the invoice “Paid” with the date, or send a receipt.

Should I include sales tax on an invoice?

Only if you're required to collect it for that sale. US rules depend on the state, and marketplaces usually collect sales tax on orders placed through them. This is general information, not tax advice.

Can I charge a late fee on an invoice?

Usually only if the customer agreed to it in advance, such as in your contract or terms, and only up to the limit your state or country allows. Write the rate and when it applies on the invoice.