UK VAT Invoice: Requirements and How to Write One (HMRC Rules)

A VAT invoice is not just an invoice with VAT written on it. In the UK it is a specific legal document with a list of required fields set out by HMRC, and your customer relies on it to reclaim their VAT. Get a field wrong or leave one off, and a business customer's accountant may reject it, delaying your payment and creating work for both of you. Get it right and it sails through, which is why every VAT-registered business should know exactly what belongs on one.

This guide covers UK VAT invoice requirements: when you must issue one, what a full VAT invoice must contain, the simplified version, VAT rates, the reverse charge, and what to do if you are not VAT registered.

When must you issue a VAT invoice?

You must issue a VAT invoice when you are VAT registered and you make a taxable supply to another VAT-registered business in the UK. You do not have to issue one to a non-registered customer or a consumer, though many businesses do anyway for their own records.

If you are not VAT registered, you must not issue a VAT invoice and must not show a VAT line at all. You simply send an ordinary invoice with no VAT. Charging VAT you are not registered to collect is a serious error, and one we flag in our common invoice mistakes guide. Registration becomes compulsory once your taxable turnover passes the threshold (£90,000 as of 2026), and you can also register voluntarily below it.

What a full VAT invoice must contain

HMRC sets out the fields a full VAT invoice must include:

• A unique, sequential invoice number
• Your business name, address, and VAT registration number
• The invoice date, and the time of supply (tax point) if different
• The customer's name and address
• A description of the goods or services supplied
• For each item: the quantity, the unit price excluding VAT, the VAT rate applied, and the amount excluding VAT
• The total amount excluding VAT
• Any cash discount offered
• The total VAT charged, in sterling
• The total amount including VAT

The two fields people forget most often are the VAT registration number and the unique sequential number. Both are mandatory, and a missing VAT number alone can invalidate the invoice for your customer's VAT reclaim. For the underlying layout these fields sit in, see our invoice format and layout guide and our invoice numbering guide.

Simplified and modified VAT invoices

Not every VAT invoice needs the full set of fields:

Type	When you can use it	What it needs
Full	Any supply, and always for larger sales	The complete list above
Simplified	Retail supplies, or any supply up to £250 including VAT	Fewer fields (see below)
Modified	Retail supplies over £250, by agreement	Full fields but shows VAT-inclusive values

A simplified VAT invoice (for supplies up to £250 including VAT) needs only: your name, address and VAT number; the time of supply; a description of the goods or services; the VAT rate for each item; and the total amount including VAT. It does not need the customer's details or a separate VAT total. This is why a shop receipt can serve as a valid VAT invoice for small purchases.

UK VAT rates

Show the correct rate against each item:

• Standard rate: 20%, covering most goods and services.
• Reduced rate: 5%, on some items such as domestic fuel and children's car seats.
• Zero rate: 0%, on most food, books, and children's clothes. Zero-rated is still a taxable supply and must be shown; it is not the same as exempt.
• Exempt: insurance, some education and health services. These fall outside VAT entirely and do not belong on a VAT invoice as a taxable supply.

If one invoice mixes rates, show the VAT for each rate separately rather than blending them. For the mechanics of applying tax to an invoice, see our how to add tax to an invoice guide.

The reverse charge

The reverse charge shifts responsibility for the VAT from you to the customer. You invoice without adding VAT but must state that the reverse charge applies. It comes up in two common situations:

• Cross-border B2B services: supplying services to a VAT-registered business overseas, where the customer accounts for the VAT in their country.
• The CIS domestic reverse charge for construction: applies between VAT-registered construction businesses in the UK where the customer is not the end user. This catches a lot of subcontractors, so if you are in the trades, check whether it applies to you.

When it applies, your invoice must clearly say something like "reverse charge: customer to account for VAT to HMRC" and show the VAT rate that would have applied. For cross-border cases generally, see our how to invoice international clients guide.

When to issue, and the tax point

You must issue a VAT invoice within 30 days of the date you supply the goods or services (or of receiving payment, if that came first). That date, the tax point, is what decides which VAT period the supply falls into, which is why HMRC wants it on the invoice when it differs from the invoice date.

Keep copies of every VAT invoice you issue, and every one you receive, for at least six years. Your VAT return depends on them, and HMRC can ask to see them.

Not VAT registered? Here is what to do

If you are below the threshold and not registered:

• Do not show a VAT line, and do not include a VAT number you do not have.
• Do not call it a "VAT invoice", since it is simply an invoice.
• Charge the plain amount, and note nothing about VAT.

Plenty of UK freelancers and sole traders operate below the threshold and invoice perfectly professionally without VAT. For the general picture, see our freelance invoice template guide, and for UK specifics including thresholds and business structures, our UK invoice generator page.

Common UK VAT invoice mistakes

• Missing your VAT registration number.
• Non-sequential or duplicate invoice numbers.
• Charging VAT when not registered.
• Blending multiple VAT rates into one figure.
• Forgetting the reverse-charge wording where it applies.
• Issuing later than 30 days after the supply.

Create a compliant VAT invoice in 60 seconds

You do not need accounting software to issue a correct VAT invoice. Invoicara's free invoice generator lets you add your VAT number, apply 20% (or a custom rate), show VAT as its own line, number invoices sequentially, and export a clean PDF that meets HMRC's requirements. Our UK invoice generator page covers the UK rules alongside the tool. No sign-up, no watermark, free forever.

For invoicing in other countries, see our Australia and USA pages, and for the basics our complete guide on how to make an invoice. Include every required field, show the right rate, mind the reverse charge, and issue within 30 days, and your VAT invoices will never be sent back.