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Pay the tax you owe. Not a penny more.

Free UK tax calculators and plain-English guides, with the calculator built into the guide — so you get from “how does this work?” to “what does it mean for me?” without leaving the page.

128 calculators tell you what you owe. TaxFly tells you what to do about it.

Free · no account · no bank connection

Free tax check
4 questions

Work expenses, uniform allowance and higher-rate pension relief go unclaimed every year. The check is free, takes a minute, and tells you how to claim direct from HMRC.

Any time of year

Most reliefs backdate four tax years

Marriage Allowance, higher-rate pension relief and employment expenses can all be claimed for years already gone — which is why a first check is usually worth several times the annual figure.

Check what you are missing

Most read guides

All guides →

Three free checks

All 21 tools →

Tax Code Check

  • Decode what the letters and numbers on your code actually mean
  • See the allowance HMRC has given you for the year
  • Spot an emergency or month-1 code before it costs you
Check my code

Find money you are owed

  • A few questions, no sign-up
  • Covers work expenses, uniform and higher-rate pension relief
  • Tells you how to claim direct from HMRC, free
Start the check

Making Tax Digital

  • Find out whether the quarterly rules apply to you yet
  • The income thresholds and the dates they start
  • What you have to send HMRC, and when
Am I affected?

Latest guides

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Most-used calculators

All 128 →

Every calculator shows its working

128 calculators and tools, from take-home pay to capital gains. Each one states the tax year it used and the rules it applied, so you can check the answer rather than take it on trust.

Ranked by page views on TaxFly. Figures are for the 2026/27 tax year and cover England, Scotland, Wales and Northern Ireland.

Tax news

All news →

Software that files it for you

Partner links

If you keep your own books, these are the packages that handle Self Assessment and Making Tax Digital.

FreeAgent

4.8
Free optionMTD ready

The freelancer and contractor favourite, free with some bank accounts.

  • Free forever with a NatWest, Royal Bank of Scotland, Ulster or Mettle business account
  • Built-in Self Assessment and MTD for Income Tax filing

From £0 with a NatWest, RBS or Mettle account, otherwise about £19/mo

See FreeAgent

QuickBooks

4.6
MTD ready

The big all-rounder with the deepest MTD track record.

  • Sole Trader plan built specifically for Self Assessment and MTD
  • Snap and store receipts, automatic bank feeds

From about £10/mo, frequent 90% off intro offers

See QuickBooks

Xero

4.5
MTD ready

The scale-up choice once you have staff, stock or VAT.

  • Huge app marketplace and the accountant industry standard
  • Strong for VAT, payroll and multi-user limited companies

From about £15/mo

See Xero

We may earn a commission if you sign up through one of these links. It never changes what we calculate, what we recommend, or the order they appear in.

About TaxFly

A UK tax reference you can check, not just trust

TaxFly is a free UK tax reference: 128 calculators and tools and 190 guides covering income tax, take-home pay, National Insurance, self-employment, VAT, capital gains, stamp duty, pensions and savings. It exists because most tax calculators online are thin, out of date or quietly wrong.

Every figure follows the official published rules, every guide is written and reviewed in-house by a named person, and nothing is behind a sign-up. We give estimates for guidance — not regulated tax advice.

Accuracy is the product

Every figure follows the published rules from GOV.UK, Revenue Scotland and the Welsh Government — including where the rules differ by nation.

Check the source

Check the tax year and assumptions beside each tool. Where a completed review is recorded, the page identifies the reviewer and date.

Free to get started

Public calculators and guides are free. An account unlocks itemised check findings. Advertising and partner links never change the maths.

Maria Moisei

Maria Moisei

Tax Accountant

UK tax accountant

Maria Moisei is a UK tax accountant working across personal tax compliance, from routine returns to the cases where an allowance or a relief has quietly been missed for years. At TaxFly she reviews the personal tax guides and the allowances that most people underclaim: the personal allowance, the personal savings allowance, marriage allowance, work-expense claims and the tax-refund routes.

View profile →

Frequently asked questions

Is TaxFly free to use?

The public calculators and guides are free to use. An account unlocks features such as itemised check findings. Advertising and labelled partner links help fund the site and do not change the calculations.

Which tax year do the calculators use?

The calculators are set to the current 2026/27 UK tax year, which runs from 6 April to 5 April. Check the year selected in each tool, especially for historical examples or future changes. A completed review is shown separately with the reviewer and date where one is recorded.

Do the calculators work for Scotland, Wales and Northern Ireland?

Yes. UK tax is regional: income tax has its own bands and rates in Scotland, and the tax you pay when buying a home is a different tax in each nation — Stamp Duty Land Tax in England and Northern Ireland, Land and Buildings Transaction Tax in Scotland, Land Transaction Tax in Wales. TaxFly applies the rules for the nation the calculation is for rather than assuming England.

How we calculate every figure →

Who writes and checks the guides?

Each guide credits its assigned author or editorial team and links to their profile. Authorship is separate from review: where a completed review is recorded, the page identifies the reviewer, date and any review note. A byline alone does not mean a qualified adviser has reviewed the page.

Meet the people behind TaxFly →

Where do the numbers come from?

From the official published rates — GOV.UK and HMRC for UK-wide taxes, Revenue Scotland and the Welsh Government where a tax is devolved. Our method for each calculation, including the assumptions it makes, is written up rather than hidden.

Read our method →

Is this tax advice?

No. TaxFly gives estimates for guidance only and is not a substitute for professional advice. For a decision that matters — a large capital gain, a property purchase, an HMRC dispute — speak to a qualified accountant or adviser, or check your position directly with HMRC.

Read the full disclaimer →

What happens to the figures I type in?

The calculators run in your browser. The salary, expenses or gains you enter are worked out on your own device and are not sent to us or stored. You only share an email address if you choose to — to subscribe, or to create an account for saving results.

Our privacy policy →

I think my tax code is wrong — what should I do?

Check the code first, then challenge it. Roughly speaking, the number in your code is the tax-free allowance HMRC thinks you are entitled to, divided by ten, and the letters describe your circumstances. The Tax Code Checker explains what yours means and what it implies for your take-home pay before you contact HMRC.

Check your tax code →

Deadlines, rate changes and what to claim

One email when something changes that affects your money. No daily send, no sponsored filler. Unsubscribe whenever.