In short: a full UK VAT invoice must show nine specific fields, starting with your VAT registration number and ending with the total VAT in sterling. Since Making Tax Digital, those records must live in compatible software — and everything must be kept for at least six years. Buyer's rule of thumb: no valid VAT invoice (or import C79), no input VAT reclaim.
The 9 mandatory fields on a full VAT invoice
These come straight from VAT Notice 700. Miss one and your customer may be unable to reclaim the VAT — which is how invoices get rejected by finance departments:
| # | Field | Notes |
|---|---|---|
| 1 | Sequential invoice number | Unique, from one or more series you control |
| 2 | Date of issue | The day the invoice is created |
| 3 | Date of supply (tax point) | Only if different from the issue date |
| 4 | Your name, address and VAT registration number | As registered — check it's your current trading name |
| 5 | Customer's name and address | The legal entity you're supplying |
| 6 | Description of the goods or services | Enough to identify them — "consultancy, June" is fine |
| 7 | Per line: quantity, unit price, VAT rate, amount excluding VAT | Plus the rate of any cash discount offered |
| 8 | VAT charged at each rate | In sterling — even if you invoice in another currency |
| 9 | Total VAT chargeable | Again in sterling |
Showing a line at 0%? That is still a VAT charge — state it as zero rather than leaving it blank, so the invoice proves the supply was zero-rated, not exempt. Reverse-charge construction invoices drop most of the VAT lines entirely but need their own special wording — see the reverse charge guide.
Full, simplified or modified: which one do you issue?
| Type | When you can use it | What it can omit |
|---|---|---|
| Full | Default — always valid, required for any B2B customer who asks | Nothing |
| Simplified | Retail sales of £250 or less including VAT | Customer details, unit prices, per-rate VAT amounts — you show just the total and the VAT rate(s) |
| Modified | Retail sales over £250, if the customer agrees | A full invoice plus VAT-inclusive totals; per-item VAT can be summarised |
Documents that are not VAT invoices
HMRC will not accept any of these as evidence for a reclaim: pro-forma invoices (essentially quotes — mark them "this is not a VAT invoice"), order confirmations, delivery notes, statements of account, and receipts that omit the supplier's VAT number. If a supplier sends any of these, ask for a proper VAT invoice before you enter the reclaim in your VAT account.
Credit notes mirror the original invoice: same fields, referencing the invoice number, with negative or clearly-labelled amounts. Issue one whenever you reduce what a customer owes — a refund for returned goods, a discount agreed after invoicing, or correcting an overcharge.
When the VAT becomes due: the tax point
The "time of supply" decides which VAT return period a sale lands in. The basic tax point is the date goods are made available or a service is performed — but it moves if you take payment or issue an invoice first (that earlier date wins), and if you invoice within 14 days after completing the work, the invoice date becomes the tax point. It matters most at quarter-ends and when VAT rates change: a job finished 29 September but invoiced 3 October usually still belongs to the September return.
What you must keep for six years
- Copies of every VAT invoice you issue (paper or digital) and every one you receive
- All credit notes and debit notes
- Your VAT account — the running summary of output tax charged and input tax claimed per period
- Import and export documents, including the monthly C79 import VAT certificate — the only valid evidence for import VAT
- Records supporting anything special: reverse-charge checks, self-billing agreements, margin-scheme workings, Flat Rate Scheme calculations
- General business records — bank statements, till rolls, order books — that reconcile to the VAT figures
Capital goods scheme and property records can need keeping for ten years, and MOSS-style scheme records likewise run longer — when in doubt, keep it.
Making Tax Digital: the records must live in software
Since April 2022, virtually every VAT-registered business must keep its VAT records digitally and file through MTD-compatible software. The required digital records are: your business name, principal place of business, VAT number and any accounting schemes used; and for each period, the output tax charged and input tax reclaimable, plus for every supply its time, value and VAT rate. The crucial wrinkle is digital links: once data enters the digital journey it must flow between systems electronically — retyping or copy-pasting figures from one spreadsheet to another breaks the link and is not compliant. Bridging software is fine; bridging by hand is not.
Correcting errors on past returns
Found a mistake? Net errors under £10,000 — or up to £50,000 if they're within 1% of your box 6 turnover — can simply be adjusted on your next return. Anything larger, or anything deliberate, must be notified to HMRC separately (online or on form VAT652). Always tell HMRC before they find it themselves: unprompted disclosure is the single biggest reducer of inaccuracy penalties.
The penalties for getting it wrong
- Late returns: the points system gives one point per missed deadline; hit your threshold and every subsequent late return costs a £200 penalty.
- Late payment: no penalty if you pay — or arrange to pay — within 15 days; then 2% of what's outstanding at day 15 and a further 2%+ at day 30, with interest (base rate + 2.5%) running alongside.
- Record-keeping failures: HMRC can charge penalties where records are inadequate to support the returns — and poor records turn a routine check into an assessment.
Frequently asked questions
What must a complete UK VAT invoice show?
Nine things: a unique sequential invoice number; the date of issue; the date of supply if different; your name, address and VAT registration number; your customer's name and address; a clear description of the goods or services; for each line the quantity, unit price, VAT rate and amount excluding VAT, plus any discount rate; the VAT amount charged per rate; and the total VAT in sterling.
Do I have to give VAT invoices to private customers?
You are only obliged to issue a full VAT invoice where your customer is VAT-registered and asks for one — typical in B2B. For private consumers an invoice is good practice but not a legal requirement, and retailers can issue simplified invoices for sales of £250 or less including VAT.
Can invoices be sent electronically?
Yes. Invoices by email or portal are fully valid provided your customer agrees to receive them that way and you can ensure authenticity of origin, integrity of content and readability. An emailed PDF satisfies all three; the UK has not (yet) mandated structured e-invoicing for B2B sales.
How long do I need to keep VAT records?
At least six years. That covers your VAT account, copies of all invoices issued and received, credit notes and import documents. Records for the capital goods scheme and some property transactions must be kept longer — up to ten years in some cases.
What's the difference between full, simplified and modified VAT invoices?
A full invoice shows every mandatory field and is the default for B2B. A simplified invoice — retail sales of £250 or less including VAT — drops the customer details, unit prices and VAT breakdown, showing just a total and the VAT rate. A modified invoice is a full invoice with VAT-inclusive totals added, used by retailers for sales over £250 when the customer agrees.
Is a pro-forma invoice a valid VAT invoice?
No. A pro-forma is essentially a quote: you cannot reclaim VAT with one and it should be clearly marked that it is not a VAT invoice. Once the supply happens, issue a real VAT invoice. The same applies to statements, delivery notes and purchase orders.
What do I do if I find an error on an old VAT return?
Net errors under £10,000 — or up to £50,000 if within 1% of your box 6 turnover — can be corrected on your next return. Larger or deliberate errors must be notified to HMRC separately, online or on form VAT652. Tell HMRC before they find it: unprompted disclosure attracts smaller penalties.
Which records must be kept digitally under Making Tax Digital?
Your business name, principal place of business, VAT number and any accounting schemes you use, plus, for each VAT period, the output tax charged and input tax reclaimable — and, for each supply, the time of supply, value and VAT rate. These must live in MTD-compatible software with digital links between systems: cutting and pasting figures between spreadsheets is not a digital link.
Sources and review
This guide was checked against GOV.UK guidance, including VAT Notice 700 (The VAT Guide), VAT Notice 700/21 (Record keeping) and Correct errors on your VAT return, on 3 August 2026. The invoice field list, £250 simplified limit, six-year retention and error-correction thresholds are current at the review date.
This guide is general information, not tax advice — check with HMRC or your accountant before relying on it for anything unusual. See our disclaimer. Spot an error? Tell us and we'll fix it.