A VAT invoice is not just a bill with tax added. It is the document your customer uses to reclaim the VAT they paid you — and if a required detail is missing, they cannot reclaim it, and the argument lands back on your desk. This one-page guide sets out what HMRC requires on a full VAT invoice, the shortcuts allowed on small invoices, and the mistakes that get input VAT refused.
| Field | What goes there |
|---|---|
| Your VAT registration number | Your 9-digit UK VAT number, exactly as HMRC issued it |
| Unique invoice number | Sequential, with no gaps — HMRC notices missing numbers |
| Invoice date (tax point) | The date the VAT becomes due, usually the date of supply |
| Your name and address | The business name registered for VAT |
| Customer name and address | Who the supply was made to |
| Description of goods/services | Enough detail to identify what was supplied |
| Net amount per line | Price excluding VAT, per rate used |
| VAT rate and amount | Rate (20%, 5% or 0%) and the VAT amount for each line |
| Gross total | The total including VAT, clearly shown |
For supplies of £250 or less including VAT, HMRC allows a simplified invoice: your name, address and VAT number, the date, a description, and the VAT rate and total VAT due. You do not need the customer's details or a per-line breakdown. Many till receipts already meet this standard. Above £250, use the full format above.
A VAT amount shown as one lump on a mixed-rate bill. If some lines are 20% and some are 5% or zero-rated, the VAT must be split by rate — a single VAT figure leaves your customer unable to prove what they can reclaim. A missing or wrong VAT number. Check a supplier's number before you pay them, not after: a valid number that belongs to a different business is one of the most common invoice-fraud patterns. Gross-only totals. An invoice that shows only the amount due, with no net/VAT split, is not a VAT invoice at all.
Typing the layout by hand is where the errors creep in — a transposed digit in the VAT number, a rate applied to the wrong line, a total that does not add up. Generate a properly formatted invoice instead:
While you are there, the same site works as an add/remove vat calculator, a flat rate scheme calculator and a reverse charge calculator — and if a new supplier hands you their VAT number, check it first with the free checker on RemoveVAT before the money moves.