What should a proper VAT invoice show?
A proper VAT invoice — called a tax invoice in the UAE and a VAT invoice by HMRC in the UK — is the document that proves VAT was charged legally. To verify VAT on any bill, look for these five things:
- The seller's VAT number — the seller's VAT registration number: a 9-digit UK VAT number after the "GB" prefix, or the 15-digit TRN on UAE invoices. No number is the first red flag — only businesses that are VAT registered may charge VAT.
- The VAT rate per line — the rate applied to each item, so you can confirm it is the correct official rate.
- The VAT amount per line — the tax charged on each item, which should add up to the invoice's total VAT.
- Net and gross totals — the net price and the VAT-inclusive total, shown separately.
- A VAT breakdown — where more than one rate appears, a VAT breakdown summing the tax per rate, so mixed-rate invoices still reconcile.
In the UK, HMRC requires full VAT invoices for supplies over £250 and allows simplified invoices below that. In the UAE, the Federal Tax Authority requires every tax invoice to show the supplier's TRN and the VAT charged in AED. If your receipt shows a VAT line but no VAT number, ask for a proper invoice — especially if your business needs to reclaim VAT on the purchase.
What VAT rate is on my bill?
Step two is confirming the VAT rate printed on the invoice is the correct official rate for that country and that type of supply. The European Commission publishes every EU VAT rate, HMRC publishes the UK rates, and the Federal Tax Authority publishes the UAE's single 5% rate:
| Country | Standard VAT rate | Check it against |
|---|---|---|
| United Kingdom | 20% | HMRC (gov.uk) |
| Germany | 19% | European Commission rate database |
| France | 20% | European Commission rate database |
| Ireland | 23% | European Commission rate database |
| UAE | 5% | Federal Tax Authority (tax.gov.ae) |
| Saudi Arabia | 15% | ZATCA |
The most common mismatch is an old or foreign rate on a local bill — for example, 19% German VAT on a UK purchase, or 15% Saudi VAT on a UAE receipt. Rates change rarely, but receipts do not update themselves: when you check a VAT amount, always compare the printed rate with the current official one. Our free online VAT calculator runs every common rate in both directions, and the country pages — the UK VAT Calculator and the UAE VAT Calculator — use the exact local rate.
How do you reverse-check the VAT from the total?
Most consumer bills show a VAT-inclusive total with the VAT amount printed underneath — but you can verify the VAT yourself from the total alone. The general rules are:
VAT amount from the gross total
VAT = gross total × VAT rate ÷ (100 + VAT rate)
At 20% VAT: VAT = total × 20 ÷ 120. At 5% VAT: VAT = total ÷ 21.
Net price from the gross total
Net price = gross total ÷ (1 + VAT rate)
At 20% VAT: net = total ÷ 1.2. At 5% VAT: net = total ÷ 1.05.
Take a £1,200 UK supplier invoice at 20% VAT. The VAT amount is £1,200 × 20 ÷ 120 = £200, so the net price is £1,000. Reverse-checking is the same in the UAE: an AED 210 restaurant bill at 5% VAT contains AED 210 ÷ 21 = AED 10 of VAT. This reverse calculation works for any rate — the table below gives the shortcut for each common one.
| VAT rate | VAT fraction of the gross total | Net-price shortcut |
|---|---|---|
| 20% (UK, France) | total ÷ 6 | total ÷ 1.2 |
| 23% (Ireland) | total × 23 ÷ 123 | total ÷ 1.23 |
| 19% (Germany) | total × 19 ÷ 119 | total ÷ 1.19 |
| 15% (Saudi Arabia) | total × 15 ÷ 115 | total ÷ 1.15 |
| 5% (UAE) | total ÷ 21 | total ÷ 1.05 |
Why not just subtract the rate from the total? Because taking 20% off £1,200 gives £960, not £1,000 — subtracting a percentage from a VAT-inclusive total always understates the net price. Always use the fraction or the division shortcut instead. The online VAT calculator does the reverse-check instantly if you want to double-check by machine.
How do you check VAT when the price excludes VAT?
Business-to-business quotes usually show prices before VAT — labelled "ex VAT" or "+ VAT". Checking these is a forward calculation: VAT = price before VAT × rate. A UK freelancer quotes £850 for a project before VAT. At 20% VAT: £850 × 0.20 = £170 of VAT, so the invoice total is £1,020. When you check the VAT amount on such an invoice, confirm the rate was applied to the discounted, final price — not to a higher list price.
This is also how to verify VAT on quotes before you accept them: multiply any quoted price by (1 + rate) and compare with the supplier's total. If the two differ, ask which figure the VAT was calculated on — most disputes about VAT start with that ambiguity. For the full worked maths in both directions, see the full VAT calculator guide.
How do you spot VAT mistakes on a bill?
Once you know how to check VAT amounts, four mistakes account for almost every wrong VAT on a bill:
- The wrong rate — the invoice uses another country's rate or an outdated one. The rate check in the section above catches this.
- VAT on goods that should be 0% or exempt — UK children's clothes and books are zero-rated, and UAE residential rent is VAT-exempt. VAT charged on these lines is simply wrong.
- The seller is not VAT registered — businesses below the registration threshold must not charge VAT at all: £90,000 of taxable turnover in the UK, AED 375,000 in the UAE. A VAT line with no VAT number on the invoice is the giveaway.
- Rounding — the VAT on your bill is a penny or cent off your own reverse-check. This is normal rounding: sellers may round per line while you rounded the total. Anything bigger than a penny or cent deserves a question.
A fifth, subtler error: VAT calculated on the pre-discount price when the bill shows a discount. The VAT amount must be based on what you actually pay — the discounted total — so reverse-check the VAT against the final figure, not the crossed-out one. The UAE 5% VAT guide shows how this works at the Gulf's single rate.
What should you do if the VAT looks wrong?
If your check shows incorrect VAT, start with the seller: ask for a corrected invoice showing the right VAT rate and VAT amount. Businesses especially should insist — you cannot reclaim VAT on an invoice with the wrong figures, and your own VAT return depends on accurate input VAT.
Keep the original receipt and any correspondence. If the seller refuses to fix it, or you suspect deliberate fraud — a common trick is charging VAT while not being registered for VAT at all — report it: HMRC runs a VAT fraud hotline in the UK, and the FTA handles tax-evasion reports in the UAE. For shoppers, overcharged VAT means you paid more than the law requires: the gross total should drop once the VAT is corrected.
Want to run the numbers yourself? The free online VAT calculator verifies any bill in seconds, and the country calculators — the UK VAT Calculator and the UAE VAT Calculator — use the exact local rates.
Frequently asked questions
How do I check the VAT amount on a receipt?
Start with the tax invoice: find the VAT line and the rate printed next to it. Then reverse-check the maths — VAT = gross total × rate ÷ (100 + rate). On a £120 UK bill at 20% VAT that is £120 × 20 ÷ 120 = £20 of VAT. If the printed VAT amount differs by more than a penny, ask the seller about it.
How do I reverse-check VAT from a VAT-inclusive total?
Use the formula VAT = total × rate ÷ (100 + rate). The shortcuts: at 20% VAT, divide the total by 6 (a £1,200 invoice contains £200 of VAT); at the UAE's 5%, divide by 21. Never just subtract the rate percentage from the total — that gives the wrong net price.
What must a valid VAT invoice show?
The seller's name and address, VAT registration number — or the 15-digit TRN in the UAE — the invoice date, a description of the goods or services, the rate applied to each line, the VAT amount, and the net and gross totals. Businesses need a valid VAT invoice to reclaim VAT on purchases.
Why is the VAT on my bill 1p more than my calculation?
Rounding. Sellers often calculate VAT per line and round each line, while a single calculation on the total rounds only once — the two can differ by a penny. If the gap is bigger than a penny, the VAT is genuinely wrong: ask for a corrected invoice.
Can a shop charge VAT if it is not VAT registered?
No. Only VAT-registered businesses may charge VAT — in the UK the registration threshold is £90,000 of taxable turnover, in the UAE it is AED 375,000. A bill with a VAT line but no registration number shown is the classic giveaway. If you paid it, ask for a refund of the wrongly charged tax.
What should I do if the VAT on my invoice looks wrong?
Ask the seller for a corrected invoice first, and keep the original plus any correspondence. Suspected fraud can be reported to the UK tax authority or the UAE's Federal Tax Authority. For cross-border EU purchases, the European Commission's rate database confirms which rate should have applied.
The 30-second version
- Read the VAT line: a proper invoice shows the seller's VAT number, the rate per line, the VAT amount, and the net and gross totals.
- Confirm the rate against the official rate for that country: 20% UK, 20% France, 19% Germany, 23% Ireland, 5% UAE, 15% Saudi Arabia.
- Reverse-check: VAT = total × rate ÷ (100 + rate). Shortcuts: 20% → total ÷ 6; 5% → total ÷ 21.
- Spot the mistakes: wrong rate, VAT on zero-rated or VAT-exempt items, VAT charged by an unregistered seller, and anything more than a penny-level rounding gap.
- If it is wrong: ask the seller for a corrected invoice, keep the original, and report suspected fraud to the tax authority.
Run the numbers in the free VAT Calculator or read the full VAT calculator guide.