Independent · not affiliated with HMRC
Could HMRC owe you money back?
Free UK tax refund estimators for 2026-27and five earlier years. We show the maths, admit the limits, and always send you to HMRC's free claim route — never a paid middleman.
- 100% free — for you and from HMRC
- Inputs never leave your device
- Working and limits shown, always
- 16
- free calculators — each with the working shown
- 6
- tax years covered, 2021-22 through 2026-27
- £0
- fees — from us, and from HMRC's own claim routes
- 0
- personal inputs sent to our servers — maths stays on your device
Pick your situation
How our rates are verified →Working on PAYE
PAYE tax refund
Estimate a PAYE tax refund from your P60 income and tax paid. See the full working, the limits of the estimate, and how to claim free from HMRC.
Free · no sign-up
P800 checker
Estimate whether HMRC's records are likely to show a P800 refund or an underpayment this year, and learn the free route to claim whichever it is.
Free · no sign-up
Income tax
Work out UK income tax for 2021-22 to 2026-27 with full band-by-band working, including Scottish rates and the £100,000 Personal Allowance taper.
Free · no sign-up
Tax code checker
Decode any UK tax code — 1257L, BR, D0, K, S/C prefixes, W1/M1 emergencies — see the allowance it implies and the warning signs of an error.
Free · no sign-up
Work expenses
Uniform tax rebate
Work out the tax relief on washing and maintaining a work uniform, using HMRC flat-rate expenses for up to four years back. Claim free.
Free · no sign-up
Mileage tax relief
Estimate mileage allowance relief on business miles in your own vehicle. Compare the 55p/25p approved rates (45p/25p before 2026/27) with what your employer paid. Claim free from HMRC.
Free · no sign-up
Tool tax relief
Estimate tax relief on tools and equipment you must buy for your job — flat-rate or actual costs — and claim free from HMRC, up to four years back.
Free · no sign-up
Professional fees
Estimate tax relief on membership fees to HMRC-approved professional bodies (GMC, NMC, RCN and hundreds more). Claim free, up to four years back.
Free · no sign-up
MOD mileage
Service personnel: estimate tax relief on journeys made in your own vehicle for duty, using HMRC approved mileage rates against what the MOD reimbursed.
Free · no sign-up
Working from home
Estimate tax relief at £6 a week for working from home — including the more generous 2020-21 and 2021-22 rules — and claim free from HMRC.
Free · no sign-up
CIS and self-employed
Family, savings and life changes
Marriage Allowance
Check eligibility and the saving from transferring £1,260 of Personal Allowance between spouses or civil partners — worth up to £252 a year, backdatable four years.
Free · no sign-up
Pension tax relief
Work out how much extra pension tax relief you can claim as a higher or additional-rate taxpayer on relief-at-source contributions — and how to claim it free.
Free · no sign-up
Leaving the UK
Moving abroad mid-year? Estimate the UK tax refund from your unused Personal Allowance and claim it free with form P85.
Free · no sign-up
Student loan refund
Repaid your student loan despite earning under the annual threshold? Estimate the refund for Plan 1, 2, 4, 5 or Postgraduate loans and reclaim free from the SLC.
Free · no sign-up
Married Couple's Allowance
Check the Married Couple's Allowance if you or your partner were born before 6 April 1935 — worth up to about £1,127 off your tax bill.
Free · no sign-up
Why so many people overpay tax
PAYE is built for speed, not precision. It guesses your year from each payslip — and life refuses to fit the guess. Six situations create the overwhelming majority of refunds:
Changed jobs or had a gap
Emergency tax codes and overlapping P45s are the single biggest cause of overpaid PAYE. A mid-year switch often leaves money behind.
Check a PAYE refundWork in construction (CIS)
20–30% deductions on gross pay almost always overshoot the real bill once van, tools and materials are counted.
Estimate a CIS rebateWear and wash a uniform
Nurses, shop workers, hospitality staff — if you maintain your own workwear, HMRC flat-rate relief applies, even for past years.
Check uniform reliefDrive or buy tools for work
Business miles at 55p a mile for 2026/27 (45p for earlier years) and tools you must supply yourself both carry relief — worth hundreds a year for many trades.
Estimate mileage reliefLeft the UK mid-year
PAYE assumes a twelve-month year. Leave early and the unused Personal Allowance usually comes back through form P85.
Estimate a P85 refundMissed earlier years
Most claims reach back four tax years. In 2025-26 the window closes on 2021-22 — after 5 April 2026 that year is gone.
Check earlier yearsHow every estimate works
1 · Enter your numbers
P60 figures, miles or fees. Everything runs on your device — your inputs are never sent to our servers.
2 · See the full working
Every result opens up band-by-band, with the year's verified rates and the limits of what an estimate can know.
3 · Claim free from HMRC
We finish by handing you the exact GOV.UK route — the same claim a refund company would charge you up to 48% to make.
The free route for every claim type
There is no claim on this site that requires a paid agent. Here is the honest map — the same destinations we hand you after every estimate:
| Claim type | Free official route | Estimate first |
|---|---|---|
| PAYE refund / P800 | GOV.UK 'claim a tax refund' service (online, free) | PAYE tax refund |
| Uniform, tools, mileage, fees | Form P87 online or by post (free) | Uniform tax rebate |
| CIS rebate | Your Self Assessment return on GOV.UK (free) | CIS tax rebate |
| Marriage Allowance | GOV.UK application — lower earner applies (free) | Marriage Allowance |
| Leaving the UK | Form P85 online with your P45 (free) | Leaving the UK |
| Working from home | Form P87 / relief microservice rules (free) | Working from home |
| Pension top-up relief | Self Assessment or HMRC letter (free) | Pension tax relief |
| Student loan over-repayment | Student Loans Company direct (free) | Student loan refund |
The honest-broker rule
The same claim HMRC gives you free — without the 30% fee
- We never take a percentage of a refund. Estimates cost nothing; HMRC's claims cost nothing.
- Every calculator names its primary GOV.UK or legislation source and the date it was last checked.
- Where 2026-27 figures are still provisional, the result says so in writing.
- How the site pays for itself — and why that never touches the maths.
Verified, versioned rates
One rate registry powers everything
Every calculator, the tax-year comparison tables and the source list draw from a single versioned registry — so the number you see on a calculator can never drift from the number on our reference pages.
- Tax year changes 2021-22 to 2026-27 — rates side by side with effective dates.
- Source registry — the GOV.UK page behind every rate we publish.
- Editorial policy — primary sources first, competitors never.
From the guides
All guides →Tax codes
D0 and D1 tax codes explained — 40% & 45%
What D0 and D1 tax codes mean, when they're correct (second jobs, pensions), when they're errors costing you money, Scotland's S D0/S D1 variants, and how to fix them free.
Read the guide
Tax codes
1257L tax code meaning — all about your pay
What the 1257L tax code really means, why £12,570 matters, when the code is right, when it hides an error, how it interacts with second jobs, benefits and past years.
Read the guide
Tax basics
What is income tax? Rates, bands and how it works
UK income tax explained from zero: what counts as income, the Personal Allowance, the 20/40/45 bands, Scotland's six rates, the £100,000 taper, and NI vs income tax.
Read the guide
Questions people actually ask us
Is RefundCalculator really free?
Yes — every estimate costs nothing, no account is needed, and we never take a percentage of anything. The site may earn referral fees on clearly labelled partner links, which never influence results. Read how we make money in the footer.
Are you HMRC or connected to the government?
No. We are an independent private publisher and are not affiliated with HMRC, the UK government or the Student Loans Company. Everything we estimate can be claimed directly from the official free services we link to.
Is it safe to enter my pay figures?
Safer than most sites: the maths runs entirely in your browser. Your inputs are never transmitted to our servers, never stored, never sold. You can verify that in your browser's network tools.
How accurate are the estimates?
Rates come from a versioned registry sourced from GOV.UK, HMRC manuals and legislation, unit-tested at every band boundary. Estimates can't see HMRC's full record (benefits in kind, other jobs), so treat them as a guide — HMRC's records are always the authority, and the free routes we link give you the official answer.
How far back can I claim?
Most income tax claims can go back four tax years. The oldest year open right now is shown with a warning on every calculator; the year dropdown defaults to the current year but applies exactly the year you pick.