How UK tax is actually structured
Income tax touches nothing until income passes the £12,570 Personal Allowance, then charges each band’s rate only on the pounds inside that band. National Insurance runs as a parallel system with its own thresholds. The band table in the result panel is the entire income tax calculation made visible — there is nothing behind it.
tax = Σ (band amount × band rate), on income above the allowance · NI runs separately on earningsWorked example · £45,000, 2026-27
- England & NI: £6,486 income tax + £2,594 NI = £9,080.
- The same salary in Scotland: £6,882 income tax — £396 more, through the six Scottish bands.
- Effective deduction rate in England: 20.2%, against a 20% marginal band.
The taper, in numbers
At £110,000, the allowance has shrunk to £7,570 and total deductions reach £37,643 — the stretch between £100,000 and £125,140 carries the harshest marginal rate in the system, roughly 60% before NI. It is the one place where a pay rise genuinely deserves a calculation before a celebration; run your own numbers rather than the rule of thumb.
Tax first, or take-home first
This page leads with the deduction; its siblings lead with what survives it. The take-home pay calculator starts from the yearly net, the salary calculator from the monthly figure, and the salary after tax calculator sits between the two. All four run the same verified engine — pick the frame that matches your question.
What’s included, and what isn’t
Every figure this calculator produces is an estimate. Here is exactly what it accounts for, and what it does not.
What’s included
- Income tax from the published GOV.UK bands — rest-of-UK or Scottish, band by band.
- The Personal Allowance, including its taper above £100,000.
- Employee Class 1 National Insurance at 8% between the thresholds and 2% above the upper limit.
- Conversion between annual, monthly and weekly figures.
What’s not included
- Pension contributions and salary sacrifice — on the roadmap; both reduce tax in ways this estimate does not yet show.
- Student loan repayments (Plans 1, 2, 4, 5 and postgraduate) — also on the roadmap.
- Tax code adjustments: benefits in kind, marriage allowance, blind person's allowance, K codes.
- Bonuses and other one-off pay, self-employment, dividends, and savings interest.
- Employer National Insurance and the apprenticeship levy, which cost your employer rather than you.
What this calculator assumes
- Uses the 2026-27 rates and thresholds published on GOV.UK (tax year 6 April 2026 to 5 April 2027).
- Applies the standard £12,570 Personal Allowance, tapered by £1 for every £2 of income above £100,000.
- Assumes a standard tax code with no adjustments, one employment, and the same pay all year.
- National Insurance uses the annual equivalents of the published thresholds; per-payday NI can differ by a few pounds.
- Scotland's six income tax bands are applied when selected. Welsh rates currently match England & NI.
Sources
Every rate and threshold above is transcribed from a primary source and re-checked on the date shown.
Frequently asked questions
What are the UK income tax bands for 2026-27?
In England, Wales and Northern Ireland: 20% basic rate up to £50,270 of income, 40% higher rate to £125,140, and 45% above — each applying only inside its band, after the £12,570 Personal Allowance. Scotland runs six bands from 19% to 48% instead. The calculator applies whichever set you select, from the GOV.UK figures.
What is the 60% tax trap?
Between £100,000 and £125,140, every £2 of extra income also removes £1 of Personal Allowance — so each additional pound is taxed at 40% and drags previously tax-free income into tax as well. The effective marginal rate on that stretch works out around 60% before National Insurance. Watch the result as you cross £100,000 in the calculator and the jump is visible.
Am I taxed at my band's rate on everything I earn?
No — this is the most persistent UK tax myth. Crossing into the higher rate does not tax your whole salary at 40%; only the pounds above the threshold are. That is why the calculator shows an effective rate well below your top band, and why a pay rise can never leave you worse off through the bands alone.
How different is Scottish income tax really?
Materially, in both directions. Scotland's starter rate taxes the first taxable slice at 19% — slightly less than the rUK basic rate — while its higher bands begin earlier and rise further, to 48% at the top. Middle and higher earners generally pay more than in the rest of the UK; the calculator's Scotland toggle shows your exact position rather than a generalisation.
Why does this include National Insurance in a tax calculator?
Because it comes out of the same payslip and most people asking 'how much tax will I pay' mean both. The result keeps them as separate lines — income tax through the bands, NI through its own thresholds — so you can see each system doing its own work.