Scotland is modelled for the current tax year. Scottish Income Tax rates and bands are applied to earned income, and Marriage Allowance eligibility uses Scotland's £43,662 cut-off rather than the rUK £50,270. National Insurance is reserved to Westminster, so it is the same across the UK by law; savings and dividend income are not devolved, so rUK rates there are correct rather than a gap.
Three limits are worth stating plainly, because they are real:
Wales is not yet separately supported. Welsh Rates of Income Tax are currently set at the same levels as England and Northern Ireland, so the Income Tax figure is right for a Welsh taxpayer today — but the calculator has no Welsh rate table, so it would not follow a divergence if one were introduced. Welsh Council Tax is not covered for the reason above. “Not yet supported” is the honest answer here, and it is better than a figure that happens to be right for a reason we are not tracking.
If you have more than one kind of taxable income — a salary plus savings interest, say, or dividends alongside a pension — then which of those the Personal Allowance is set against changes what you owe. Section 25(2) of the Income Tax Act 2007 is explicit about the answer: allowances must be deducted “in the way which will result in the greatest reduction in the taxpayer’s liability to income tax”. There is no default order in law. The right allocation is whichever one leaves you paying least, and it differs from person to person.
This calculator works out that allocation rather than assuming one. It compares every allocation that could be optimal and uses the cheapest. A worked example: on £45,000 of employment income with £7,000 of savings interest, putting the whole £12,570 allowance against the salary gives a bill of £8,132. Splitting it — £7,300 against the salary, £5,270 against the interest — gives £8,032. The second answer is the correct one, and it is £100 cheaper.
This is worth stating explicitly because it is a known industry-wide failure point. HMRC’s own PAYE reconciliation system was reported in September 2026 to be getting it wrong, with around 107,000 calculations pulled for manual review. Software that allocates the allowance in a fixed order will agree with this calculator for most people and quietly overstate the bill for the rest — the ones with a mix of income types, typically somewhere between £30,000 and £125,000, where the allowance, the starting rate for savings, the Personal Savings Allowance and the dividend allowance all interact.
Two notes on scope. The allocation is worked out for Scottish taxpayers against Scottish bands, not rUK ones — and because the Scottish rate ladder is different, a Scottish taxpayer’s best allocation is often not the same as an otherwise identical rUK taxpayer’s. And this flexibility is being withdrawn: from 6 April 2027 the law will require the allowance to go against non-savings income first. That change applies to 2027/28 onwards, not to the years modelled here.
Freedom Day is counted forward from 1 January, not from 6 April. The tax rules behind it are not: the rates, bands and thresholds applied are a single tax year’s parameter set, and the UK tax year runs 6 April to 5 April. The two axes do not line up, and that is a deliberate choice rather than an oversight.
The reason is that Freedom Day is a communication of an effective rate, not a second calculation. The underlying figure — the share of your labour income taken in tax — is the same number either way; only the date it is projected onto changes. Projected onto a calendar year, “you stop working for the government on 14 May” (to take an illustrative date) is a sentence a reader can place against a year they already live in. Projected onto the tax year it would read as a count of working days after 6 April, which is arithmetically identical and means nothing to anyone.
What this costs: a Freedom Day date is not a claim that on that specific calendar date your tax was paid off. Tax is deducted every payday across the tax year, not front-loaded into January. The date is a rate made visible on a familiar axis, which is why it sits alongside the “≈” mark’s logic — your figures, plus a stated modelling assumption — rather than the “✓” mark’s.
Two consequences follow, and both are real:
MyTaxReality is a model, not a tax return and not an HMRC calculation. It does not know your tax code, any HMRC determination made in your case, or any circumstance you have not entered. It gives no financial or tax advice and makes no recommendation.
Corrections to individual figures are recorded in the project changelog, including the two National Insurance basis corrections made in August 2026.