Once a business is registered, its invoices are tax documents, not just payment requests. They feed the customer's bookkeeping and your own, and they have to hold up if either side is audited. That raises the bar on a few details a sole trader can be relaxed about.
Put the full legal identity on every invoice
The customer's accounts team needs your registered business name exactly as it is recorded, your trading address, and your registration numbers: a company or business number where your jurisdiction issues one, and your VAT, GST, or sales-tax number if you are registered. In many countries a B2B customer cannot enter the invoice into their own tax records without your tax number, and the invoice will be sent back. Match the customer's legal entity too, not just the name of your contact there.
Quote the purchase order number
If the customer runs a procurement process, they issued a purchase order, and their payment system will match your invoice against it before releasing money. A missing or wrong PO number is one of the most common reasons a correct invoice sits unpaid. Ask for the PO before you send, print it near the top, and make sure the line items and total match what the PO authorised — if the order changed, get a revised PO rather than invoicing over the old one.
Make remittance effortless
State exactly how to pay: bank name, account number and routing or sort code, IBAN and BIC for international payments, and any payment-portal details the customer uses. Ask them to quote the invoice number and PO number on the remittance so you can reconcile it without guesswork. If you offer an early-payment discount — 2% for payment within ten days, say — state the terms and the discounted amount so there is nothing to calculate.
Charge tax deliberately
The tax line is a decision, not a default. Whether you add VAT, GST, or sales tax, and at what rate, depends on your registration, the customer's location, and the nature of the goods or services. Domestic sales usually take your local rate; cross-border sales, digital services, and sales to other registered businesses often follow separate rules such as reverse charge or destination-based rates. Set the rate for the specific transaction and confirm your treatment with an accountant.
Keep the numbering and the status current
Run one sequential series with the year in the prefix — INV-2026-0184 — and
allocate a number only when you actually issue the invoice. If you cancel one,
keep the number and mark it void. Give every invoice a status you maintain: sent
when it goes out, paid when the money clears, with the date and reference
recorded. That single habit gives you an accurate receivables figure and a clean
trail for your accountant at year end.
Retain the invoices you sent
Most tax authorities require you to keep issued invoices for a number of years — often between five and ten. Store the actual document you sent, as a PDF, not a version regenerated later from changed data. If you need to correct one, issue a credit note referencing the original number and then a fresh invoice, rather than editing and resending.
Before you send
- Your registered business name, address, and registration and tax numbers
- The customer's legal entity, billing address, and PO number
- A unique number from one unbroken yearly sequence
- Issue date and a due date as a real date
- Line items matching the purchase order, with quantities and unit prices
- The correct tax line for this specific sale
- Full remittance details and the references to quote
- Payment terms and any early-payment discount
- A maintained status: sent, then paid with date and reference
Set your order lines and tax rate above and download the PDF. A free NeatDue account keeps customers on file, tracks each invoice's status, and numbers the series for you.