# How to Write an Invoice (UK)

> An invoice is a formal request for payment that records what you supplied and what you are owed. This UK guide covers exactly what to put on one, the VAT rules, and how to get paid faster.

*Section: Business — By Marcus Vale (Editor-in-Chief & Business & Markets Editor) — Published July 11, 2025 — 5 min read*

Canonical URL: https://dailyjunction.org/business/how-to-write-an-invoice
Tags: invoicing, small business, getting paid, accounting, uk business

## Key takeaways

- An invoice is a formal, dated request for payment that itemises what you supplied and the total due.
- Every invoice needs a unique number, your details, the customer's details, a clear description and the amount.
- VAT-registered businesses must include extra information, including their VAT number and the tax charged.
- Clear payment terms and a due date make it far more likely you will be paid on time.
- This is general business information, not tax or legal advice.

Sending an invoice is how most businesses actually get paid — yet a surprising number are scrappy, unclear or missing details that the law requires. A well-built invoice does two jobs at once: it satisfies the rules, and it makes it easy and obvious for the customer to pay you promptly. This guide walks through what to put on a UK invoice, when VAT applies, and the small touches that get cash in faster. *This is general business information, not tax or legal advice.*

## What an invoice is

**An invoice is a formal, dated document that requests payment, recording what you supplied to a customer and the total they owe.** It is more than a polite note — it is a commercial record that both sides rely on for accounts and tax.

It helps to be clear about what an invoice is *not*. A **quote** is an estimate of price *before* work begins. A **receipt** confirms payment *after* it has been made. An invoice sits in between: the request for money once goods or services have been delivered. Keeping these distinct avoids confusion and looks professional. When you record the invoice in your books also depends on whether you use [cash or accrual accounting](/business/cash-vs-accrual-accounting), which we cover separately.

Getting invoicing right is part of the wider discipline of managing money in a business. Our guide to [cash flow in a small business](/business/cash-flow-management-small-business) explains why the timing of payments matters as much as the amounts.

## What every UK invoice must include

There is a core set of details that should appear on any invoice. Leaving them out can delay payment or cause problems with your records.

- **The word "invoice"** — so there is no doubt what the document is.
- **A unique invoice number** — sequential and never repeated, so each can be tracked.
- **Your business name and address**, and contact details. A sole trader uses their own name and any trading name; a limited company must show its registered company name.
- **The customer's name and address**.
- **The invoice date**, and the date the goods or services were supplied if different.
- **A clear description** of what you are charging for — itemised if there is more than one thing.
- **The amount due** for each item and the total.
- **Payment terms and a due date**, plus how to pay.

For a limited company, there are extra requirements, such as showing the full registered company name and, often, the registered number. It is worth confirming the current detail on GOV.UK, since the rules differ slightly by business type.

## The VAT rules

VAT is where invoices get more involved, and the rule depends entirely on your status.

If your business is **not VAT-registered**, you do not charge VAT and your invoice simply shows the amounts due. You must register once your taxable turnover passes the VAT threshold, and you can choose to register voluntarily below it.

If your business **is VAT-registered**, you must issue a proper **VAT invoice**, which includes everything above plus:

- your **VAT registration number**,
- the **tax point** (the date for VAT purposes),
- the **rate of VAT** applied to each item,
- the **amount of VAT** charged, and
- the total **excluding** and **including** VAT.

Because thresholds and the finer points change, always check the current position on GOV.UK rather than relying on an old figure. Whatever your status, keep copies of every invoice — they are a key part of your records and you may need them at tax time. The totals on your invoices also feed straight into your accounts, including your [profit and loss statement](/business/what-is-a-profit-and-loss-statement), so accuracy here pays off later.

## A simple invoice layout

You do not need fancy design — clarity beats decoration. A clean structure might look like this:

| Section | What goes here |
|---|---|
| Header | The word "Invoice", your logo or business name, invoice number and date |
| From / To | Your details and the customer's details |
| Body | Itemised description, quantity, unit price and line totals |
| Totals | Subtotal, VAT if applicable, and the grand total due |
| Footer | Payment terms, due date and how to pay |

Spreadsheet templates, free online tools and accounting software all produce this format. The important thing is consistency: a tidy, repeatable layout makes your business look organised and your invoices easy to process at the other end.

## Setting terms that get you paid

The mechanics matter, but so does the psychology of prompt payment. A few habits make a real difference:

1. **State a clear due date.** "Payment due within 14 days" or a specific calendar date works far better than a vague "on receipt".
2. **Make paying easy.** Include your bank details or a payment link. Friction loses you days.
3. **Invoice promptly.** Send the invoice as soon as the work is done — delays at your end invite delays at theirs.
4. **Use the invoice number in reminders.** It helps the customer locate it quickly.

Under UK law, if you do not agree a payment period, payment is generally due within 30 days. For overdue commercial invoices, you may also be entitled to claim **statutory interest** and a fixed recovery cost — a useful backstop, though a good relationship and clear terms usually prevent things getting that far.

## Chasing late payments

Even with everything in order, some invoices run late. A calm, escalating approach works best:

- **A friendly reminder** a day or two after the due date — often it is simply an oversight.
- **A firmer follow-up** referencing the due date and the amount, sent in writing.
- **A formal notice** if it remains unpaid, setting out that you may add statutory interest and recovery costs.
- **Escalation** as a last resort, such as the small claims process or a specialist commercial debt recovery firm — for example, [Merion](https://merion.com.au) handles commercial collections for Australian creditors.

GOV.UK sets out your rights on late commercial payments, including how interest is calculated. Keeping records of every invoice and reminder puts you in a strong position if a dispute ever arises.

## The bottom line

An invoice is a formal request for payment that records what you supplied and what you are owed — and getting it right is the difference between being paid promptly and chasing for weeks. Include the core details and a unique number, follow the VAT rules if you are registered, set clear terms with a due date, and make paying easy. Do that consistently, and most invoices look after themselves.

## Frequently asked questions

### What must a UK invoice include?

At a minimum: the word 'invoice', a unique invoice number, your business name and address, the customer's name and address, the invoice date, a clear description of what you supplied, the amount due and the payment terms. VAT-registered businesses must add more, including their VAT number. This is general information, not tax advice.

### Do I need to charge VAT on my invoices?

Only if your business is VAT-registered. Registration is required once your taxable turnover passes the VAT threshold, and you can register voluntarily below it. If you are registered, you must issue VAT invoices showing the tax; if not, you do not charge VAT. Check current rules and thresholds on GOV.UK.

### How long should I give customers to pay?

Payment terms are up to you and the customer, but 14 or 30 days is common. State the due date clearly on the invoice. Under UK law, if no date is agreed, payment is generally due within 30 days, and you may be entitled to charge interest on late commercial payments.

### What can I do if an invoice is not paid?

Start with a polite reminder, then a firmer follow-up referencing the due date. For overdue business debts you may be able to add statutory interest and a fixed recovery charge. If it remains unpaid, options include a formal demand or the small claims process. GOV.UK explains your rights.

## Sources

- [GOV.UK: Invoicing and taking payment from customers](https://www.gov.uk/invoicing-and-taking-payment-from-customers)
- [GOV.UK: Late commercial payments interest and debt recovery](https://www.gov.uk/late-commercial-payments-interest-debt-recovery)
- [GOV.UK: VAT record keeping](https://www.gov.uk/vat-record-keeping)

---
Daily Junction — https://dailyjunction.org/business/how-to-write-an-invoice