What to Include on an Invoice UK: A Complete Checklist (2026)

Sending an invoice in the UK might seem straightforward, but including the right information protects you legally, speeds up payment, and keeps HMRC happy. Whether you're a freelancer, sole trader, or small business owner, this checklist covers exactly what to put on every invoice.

The Legal Requirements

UK law requires different information depending on whether you are VAT registered.

If You're Not VAT Registered

There is no strict legal format for non-VAT invoices, but you should always include:

• Your name and address (or business name and address)
• Your client's name and address
• A unique invoice number
• The date the invoice was issued
• A description of the goods or services provided
• The total amount due
• Payment terms (e.g. payment due within 30 days)

If You're VAT Registered

VAT-registered businesses must issue a VAT invoice for all taxable supplies. These must include:

• Your VAT registration number
• The VAT rate applied (standard 20%, reduced 5%, or zero-rated)
• The VAT amount charged
• The net amount before VAT
• The gross total including VAT

HMRC has clear VAT invoice requirements — get these wrong and your client cannot reclaim the VAT they've paid.

Full Invoice Checklist

Use this as your template every time:

Your Details

• [ ] Your full name (or business name)
• [ ] Your address
• [ ] Your email address or phone number
• [ ] Your VAT number (if registered)
• [ ] Your company number (if a limited company)

Client Details

• [ ] Client's full name or business name
• [ ] Client's address
• [ ] Contact name (if relevant)

Invoice Details

• [ ] Unique invoice number
• [ ] Invoice date
• [ ] Payment due date
• [ ] Purchase order number (if your client requires one)

Line Items

• [ ] Description of each product or service
• [ ] Quantity
• [ ] Unit price
• [ ] VAT rate (if applicable)
• [ ] Line total

Totals

• [ ] Subtotal (before VAT or discounts)
• [ ] Discount amount (if applicable)
• [ ] VAT amount (if applicable)
• [ ] Total amount due

Payment Information

• [ ] Bank account number and sort code
• [ ] Payment reference (e.g. invoice number)
• [ ] Accepted payment methods
• [ ] Late payment terms (optional but recommended)

What Happens If You Miss Something?

For non-VAT invoices, a missing field won't get you into legal trouble, but it can slow down payment. Clients often delay paying when they need to chase you for missing information.

For VAT invoices, missing required fields can:

• Prevent your client from reclaiming VAT
• Trigger HMRC queries
• Result in penalties for incorrect record-keeping

Invoice Numbers: Why They Matter

Every invoice you send must have a unique, sequential number. This is important for:

• Your own bookkeeping
• HMRC record-keeping requirements
• Your clients' accounts

There's no required format — INV-001, 2026-001, or 00001 all work. What matters is that each invoice has a unique number and they don't repeat.

Payment Terms

Always include your payment terms on every invoice. The UK default is 30 days from invoice date, but you can set your own — 7, 14, or 30 days is common for freelancers.

Under the Late Payment of Commercial Debts Act 1998, if a business doesn't pay you within your agreed terms, you're legally entitled to:

• Charge 8% + Bank of England base rate interest on overdue amounts
• Add a fixed debt recovery fee (£40–£100 depending on the amount)

Include a line like: "Payment due within 30 days. Late payments may be subject to statutory interest under the Late Payment of Commercial Debts Act 1998."

Professional Extras (Not Required, But Recommended)

• Your logo — adds credibility, especially for new clients
• Thank you note — builds goodwill
• Notes section — useful for project references or terms
• Currency — essential if working with international clients

Create a UK Invoice in Minutes

Billdrop is a free UK invoice generator that includes all required fields automatically. Create a professional invoice, download as PDF, and send — no account needed.

Just fill in your details, add your line items, and download. The invoice number increments automatically so you're always in sequence.

Create a free UK invoice →

Summary

A proper UK invoice should always include:

1. Your details + client details
2. Unique invoice number + date + due date
3. Description of work with quantities and prices
4. VAT details (if registered)
5. Total amount due
6. Your bank details and payment terms

Miss any of these and you risk delayed payment or HMRC complications. Get them all right and you look professional, get paid faster, and stay compliant.