About TaxSimple
A free, independent UK tax calculator built on official HMRC rates — and a clear account of how our numbers are worked out.
Our methodology
Every estimate starts from your taxable income and the allowances you qualify for. We deduct your personal allowance (£12,570 for both 2025/26 and 2026/27, tapered by £1 for every £2 of income above £100,000), apply the correct income tax bands for your region, and add Class 4 National Insurance where it applies. Scotland’s separate bands (19% to 48%) are handled automatically when you select your region.
The calculator reflects current law for the 2025/26 and 2026/27 tax years. That includes the abolition of mandatory Class 2 National Insurance for the self-employed from 6 April 2024, the 6% Class 4 main rate, the post-2020 mortgage interest tax credit for landlords, dividend and savings allowances, and payments on account for bills over £1,000. We show a full band-by-band breakdown so you can check the workings — we don’t hide the calculation behind a single number.
TaxSimple runs entirely in your browser. We don’t ask you to sign up, and your figures are not stored on our servers.
Where our rates come from
All thresholds and rates are taken directly from HMRC and gov.uk guidance. The primary sources we rely on:
How we keep figures current
We review our rates against published HMRC guidance after each Budget and at the start of every tax year. The headline income tax thresholds are frozen until April 2028, but National Insurance rates, allowances, and rules can change at any fiscal event — so we re-check them on that cadence.
Tax rules last reviewed against HMRC guidance: April 2026.
TaxSimple is built and maintained by Omkar Sarswat, an independent developer. It applies HMRC’s published rules directly and is not a regulated tax adviser.
TaxSimple is a calculation tool, not a substitute for professional advice. For complex situations — inheritance, capital gains on property, non-UK residence, or anything you’re unsure about — we recommend confirming with HMRC directly or a chartered (ACA/CTA/ATT-qualified) tax adviser before you file. You remain responsible for the accuracy of your own HMRC submission.