How to Write an Invoice
Create clear, compliant UK invoices with all the details HMRC and your customers expect.
A clear, accurate invoice is how you turn completed work into money in the bank. Get it right and you are paid promptly, your records reconcile cleanly, and you stay on the right side of HMRC. Get it wrong, and you risk disputes, delayed payment, and queries at year end. This guide explains exactly what a UK invoice should contain, how the rules differ if you are VAT-registered, and the practical habits that keep your billing tidy. It sits within our invoicing and getting paid hub , where you will find related guidance on terms and payments.
What every invoice must show
Whether you trade as a sole trader or a limited company, a basic invoice should clearly identify who is billing whom, for what, and how much. At a minimum, include:
- A unique invoice number (see numbering below)
- Your business name and address, and a contact point
- The customer’s name and address
- The invoice date (and the supply date, if different)
- A clear description of the goods or services supplied
- The quantity and unit price for each line
- The total amount due
- Your payment terms and accepted payment methods
If you trade as a limited company, you should also show your full registered company name as it appears at Companies House, your registered office address, and ideally your company registration number. You do not have to list every director, but if you name one you must name them all.
VAT invoice requirements
If you are VAT-registered, your invoice becomes a VAT invoice and must carry extra detail so your customer can reclaim the tax. In addition to the basics above, a full VAT invoice should show:
| Required detail | What to include |
|---|---|
| VAT registration number | Your unique VAT number issued by HMRC |
| Invoice number | A unique number from a sequential series |
| Tax point | The date the supply took place for VAT purposes |
| Net amount | The price of each item excluding VAT |
| VAT rate | The applicable rate for each line |
| VAT amount | The tax charged, shown in sterling |
| Total | The gross amount including VAT |
Where different items attract different rates, show the rate against each line and a separate subtotal per rate. If you are not VAT-registered, you must not charge or show VAT on your invoices. For help deciding when registration applies, see our guide on when to register for VAT , and once registered, how to complete a VAT return .
Numbering and sequencing
Every invoice needs a unique, sequential number. Sequencing matters because it lets you, your accountant, and HMRC confirm that no invoice is missing or duplicated. A few practical points:
- Pick a format and stick to it, for example
INV-0001or2026-014 - Never reuse a number, even for a cancelled invoice
- If you void an invoice, keep a record rather than deleting it, so the sequence stays intact
- Prefixes can help if you bill multiple ventures or clients, but keep the underlying run continuous
Good software handles this automatically, removing the risk of accidental gaps or repeats.
Payment terms and methods
Your invoice should state plainly when payment is due and how the customer can pay. Common terms include payment on receipt, within 14 days, or within 30 days, but the right choice depends on your sector and cash flow. Set these deliberately rather than by default, our guide to setting payment terms walks through the trade-offs.
List the methods you accept, such as bank transfer, card, or direct debit. Offering more ways to pay generally speeds things up, and you can learn more in taking card and online payments . If you charge late payment interest or fees, state the policy clearly on the invoice itself.
Adding your bank details
If you accept bank transfer, the customer needs your details on the invoice. Include:
- The account name (matching your business name)
- The sort code and account number
- A payment reference, ideally the invoice number, so payments reconcile automatically
A clear reference is the single easiest way to avoid chasing unmatched payments later.
Invoices for sole traders versus companies
The core information is the same, but the identification differs:
- Sole traders invoice under their own name, or a trading name with their own name shown. Include your business address as a contact point. There is no company number to quote.
- Limited companies must use the full registered name and registered office, and should quote the company number. This reinforces that the contract is with the company, not you personally.
For wider context on each structure, see our self-employed and sole traders hub and the limited company finances hub .
Credit notes and corrections
If you make a mistake, never simply edit or delete an issued invoice. Instead, raise a credit note that references the original invoice number and cancels all or part of the value. This preserves a clean audit trail and keeps your VAT records consistent. Then issue a corrected invoice with a new number if needed.
For VAT-registered businesses, the credit note adjusts the VAT you have accounted for, so it must be dated and recorded properly. If an error has already flowed through to a submitted return, see correcting VAT return errors .
Sending and storing invoices
You can send invoices by email as a PDF, through accounting software, or, increasingly, as structured e-invoices. To understand the direction of travel, read what is e-invoicing .
Whatever the format, you must keep copies. As a general rule, retain business records, including invoices, for at least six years. Under Making Tax Digital, many businesses must keep these records digitally and submit using compatible software, which makes a tidy invoicing routine even more valuable. Storing everything in one system also makes year-end far smoother.
For more billing tasks and templates, browse our invoicing and payments guides .