Domestic reverse charge or overseas services? If you need to invoice zero-VAT under CIS reverse charge or B2B overseas rules, our Reverse-Charge VAT Invoice Generator produces compliant wording with the required customer VAT reference.
How do I calculate my UK VAT return?
For each VAT quarter: output VAT (VAT you charged clients) minus input VAT (VAT on eligible business purchases) equals VAT owed to HMRC. Due one month and seven days after each quarter end, via MTD-compatible software.
Key takeaways
- Standard scheme: track output and input VAT separately
- Flat rate scheme: fixed % of gross turnover (simpler)
- MTD is mandatory for all VAT-registered businesses
- Filing deadline: 1 month + 7 days after quarter end
- Set aside 15-17% of gross invoiced amounts as VAT buffer
Editorial: Calculator maintained by the FreelanceToolkit UK editorial team using HMRC's current VAT-return boxes definitions and 2025/26 filing thresholds. Editorial policy · Sources & methodology · How we test tools.
In this guide
This calculator produces the numbers you'd enter on a UK VAT return (boxes 1-9) at the end of a VAT quarter. It's a working aid — not the filing itself. For actual filing you need MTD-compatible software connected to HMRC's API. The calculator helps you sanity-check the numbers before filing, particularly if you're new to VAT.
Worked example
You invoiced £28,000 net (£33,600 gross with 20% VAT) to UK clients. Your VAT-bearing business purchases totalled £4,200 gross (£3,500 net + £700 VAT). Box 1 (VAT on sales): £5,600. Box 4 (VAT on purchases): £700. Box 5 (net VAT to pay): £4,900. Box 6 (net sales): £28,000. Box 7 (net purchases): £3,500. £4,900 is due to HMRC one month plus seven days after the quarter end. Setting aside 15-17% of gross turnover into a dedicated VAT-savings account monthly makes the quarterly payment painless.
At-a-glance comparison
| Box | What it holds | Common freelance content |
|---|---|---|
| Box 1 | VAT due on sales | 20% of your net invoiced sales (standard rate) |
| Box 2 | VAT due on EU acquisitions | Rarely used post-Brexit (Northern Ireland scenarios) |
| Box 3 | Total VAT due (Box 1 + Box 2) | Auto-calculated |
| Box 4 | VAT reclaimed on purchases | Input VAT on eligible business purchases |
| Box 5 | Net VAT to pay/reclaim | Box 3 minus Box 4 |
| Box 6 | Total value of sales (net) | All sales including zero-rated and outside-scope |
| Box 7 | Total value of purchases (net) | All purchases including exempt |
| Box 8/9 | NI-related (goods to/from) | Usually blank for services businesses |
Decision tree
Answer these questions in order — the first 'yes' with a clear steer usually gives you the answer.
- Are you on the standard scheme?
Track output and input VAT separately. - Are you on the Flat Rate Scheme?
Pay a % of gross turnover. Different calculator applies. - Are you on Cash Accounting?
Only VAT on invoices actually paid — helps cashflow on long-payment-terms clients. - Do you have EU-VAT services purchases?
Reverse-charge applies — you self-account on both sides. - Have you missed the filing deadline?
Penalties start at £200 + potential VAT default surcharge. File asap even if late. - Are you unsure about a specific transaction?
Get a quick review from an accountant. VAT errors compound quarterly.
Sources & official references
Every rate and threshold in this guide traces back to a published UK official source. All updated for the 2025/26 tax year.
Related on FreelanceToolkit UK
Your sales (output VAT side)
Your purchases (input VAT side)
Your VAT return — by box
Box-by-box detail
| Box | Label | Amount |
|---|
What each box on a UK VAT return means
The standard UK VAT return has nine boxes. This calculator fills in all of them for you based on plain-English inputs.
Output VAT side
- Box 1 — VAT due on sales and other outputs (the VAT you charged customers, plus reverse-charge purchases self-accounted for).
- Box 2 — VAT due on acquisitions of goods from EU member states (post-Brexit, almost always £0 for UK service businesses).
- Box 3 — Total VAT due (Box 1 + Box 2).
Input VAT side
- Box 4 — VAT reclaimed on purchases (input VAT you can recover, including reverse-charge purchases which also went into Box 1).
- Box 5 — Net VAT to pay or reclaim (Box 3 − Box 4). Positive = you owe HMRC. Negative = HMRC owes you.
Totals
- Box 6 — Total value of sales excluding VAT (sum of all standard, reduced, zero-rated and reverse-charge sales; excludes exempt sales).
- Box 7 — Total value of purchases excluding VAT.
- Box 8 — Total value of goods supplied to EU (post-Brexit: usually £0 for UK businesses; goods supplies need separate customs declarations).
- Box 9 — Total value of goods acquired from EU (post-Brexit: usually £0).
The reverse-charge trick
Reverse-charge purchases (cloud services from US suppliers, EU professional services) require you to self-account for the UK VAT at 20%. You add the notional VAT to Box 1 (as if you'd charged it to yourself), and then immediately reclaim the same amount in Box 4. The two cancel out — your net VAT bill is unchanged — but you must declare both sides. Failing to do this is one of the most common VAT mistakes HMRC catches in inspections.
Worked examples
Sales: £20,000 at 20% (UK clients) + £5,000 reverse charge (US B2B clients).
Purchases: £3,000 UK software/tools at 20% + £600 of Google/Meta ads (reverse charge).
Box 1: £4,000 (UK output VAT) + £120 (RC on Google ads) = £4,120.
Box 4: £600 (UK input VAT) + £120 (RC reclaim) = £720.
Box 5: £3,400 owed to HMRC.
Box 6: £20,000 + £5,000 = £25,000.
Box 7: £3,000 + £600 = £3,600.
Same designer as above, but bought a £4,000 (ex VAT) laptop this quarter. Adds £4,000 to Box 7, £800 of input VAT to Box 4 → net VAT due drops from £3,400 to £2,600. Capital purchases above ~£2,000 can produce a Box 5 refund quarter if your output VAT is low.
No. This is a working calculator only — it computes the figures you'd then enter into HMRC's MTD-compatible bookkeeping software (FreeAgent, Xero, QuickBooks, Sage, etc.) or your accountant's portal. Direct submission to HMRC requires MTD-compatible software with an API connection. See our MTD for VAT explainer for the software you need.
Box 6 is total sales excluding VAT — your standard, reduced, zero-rated and reverse-charge sales added together (exempt sales are excluded). Box 7 is total purchases excluding VAT — your standard, reduced, zero-rated and reverse-charge purchases added together. These figures are essentially "turnover for the period" and "spend for the period" — HMRC uses them for analytics and inspection targeting.
No. Zero-rated sales (food, books, children's clothes, exports) are VAT-able but at 0% — they go in Box 6 and allow you to reclaim input VAT. Exempt sales (insurance, financial services, education) are outside the scope of VAT entirely — they're excluded from Box 6 and you cannot reclaim input VAT on costs that relate solely to making them. Get this wrong and you under-reclaim input VAT or over-state Box 6.
For B2B services you buy from overseas suppliers (like Google or Meta) or services you sell to overseas business customers, no VAT is charged on the invoice. Instead, the buyer self-accounts for the VAT in their own VAT return — adding the notional VAT to Box 1 (as if they'd charged themselves) and reclaiming the same amount in Box 4. It's a paperwork exercise that cancels out, but it must be declared. See our full reverse-charge guide.
Quarterly, with submission and payment both due one calendar month and seven days after the end of the VAT period. So a Q1 return covering Jan–Mar is due by 7 May. You'll have specific quarter dates assigned when you register — they're not always aligned to calendar quarters. Annual Accounting Scheme members submit one annual return instead, with interim payments.
HMRC will refund you — typically within 10 working days of submission if you're set up for BACS refunds. Repayment claims often trigger an inspection if they're unexpected or large; have your supporting invoices and the rationale ready.
You can correct net errors up to £10,000 (or 1% of Box 6 turnover, up to £50,000) by adjusting your next VAT return. Larger errors must be notified separately via form VAT652. Deliberate misstatements carry penalties of 30–100% of the under-declared tax. Honest errors disclosed before HMRC discovers them attract much smaller penalties.
Quick VAT deadline planner
Interactive tool. Estimates only — always verify with the full calculator or HMRC guidance for final decisions.
This calculator computes the figures for a standard-scheme UK VAT return. It does not submit to HMRC — for that you need MTD-compatible software with an API connection. Always cross-check against your bookkeeping records before submitting, and consult an accountant for complex situations (partial exemption, margin schemes, second-hand goods, TOMS).