Welsh Income Tax Calculator United Kingdom

How Welsh income tax works

Welsh income tax is the part of UK Income Tax that the Senedd controls, and it applies to anyone whose main home is in Wales. It is not an extra tax on top of the UK bill. For a Welsh taxpayer the UK basic, higher and additional rates are each reduced by 10p in the pound, and the Senedd sets a Welsh rate for each band to add back. The two together give the rate you pay.

Since the power began, the Senedd has set the Welsh rate at 10p in every band, which restores the UK rates exactly. A Welsh taxpayer on £40,000 pays the same Income Tax as someone on £40,000 in Bristol or Belfast. What differs is where the money goes: 10p of the tax on each pound of taxable income goes to the Welsh Government to fund devolved services, and the rest goes to the UK Exchequer.

Enter your income and any taxable benefits, pension contributions or Gift Aid donations, and the calculator shows the total tax, how much funds Wales, how much goes to Westminster, the rate on your next pound and what the same income would cost in the rest of the UK.

A worked example

On £40,000, £27,430 is taxable after the personal allowance, all in the basic rate band. The tax is £5,486, the same as elsewhere in the UK: £2,743 funds the Welsh Government and £2,743 goes to the UK Government.

What income the Welsh rates cover

The Welsh rates apply only to non-savings, non-dividend income: employment earnings, self-employed profit, pension income including the State Pension, taxable benefits in kind and profit from letting property.

Everything else follows UK rules. Bank and building society interest is taxed at UK savings rates, with the starting rate for savings and the Personal Savings Allowance applied as normal. Dividends are taxed at UK dividend rates, and capital gains are outside Income Tax. A Welsh taxpayer with investments will find only part of their tax return affected by the Welsh rates.

National Insurance is UK-wide with no devolved element, so Welsh and English payslips on identical pay show identical National Insurance.

The allowance and bands are still set in Westminster

The personal allowance, the point at which it starts to be withdrawn and the band limits are all reserved to Westminster.

The personal allowance is the income taxed at nothing. Above £100,000 it is withdrawn at £1 for every £2 of adjusted net income until none is left. Because the withdrawn allowance is itself taxed, income in that range has a marginal rate well above the higher rate, and the calculator shows it.

The band limits are measured on taxable income, after the allowance. The basic rate band has a fixed width, so tapering the allowance pushes more income into the higher rate band rather than widening the basic band. A calculator that treats the basic band as ending at a fixed income figure understates the tax of anyone earning over £100,000 by thousands of pounds.

Reading the split between Cardiff and Westminster

The Welsh Government share is the taxable income in each band times the Welsh rate for that band. The UK Government share is the same taxable income times the UK rate after the 10p reduction.

For a basic rate taxpayer that is an even split: 10p to Cardiff and 10p to Westminster out of every 20p of tax. In the higher rate band the Welsh share is 10p out of 40p, and in the additional rate band 10p out of 45p, so the proportion funding Wales falls as income rises even though the amount in pounds grows.

The comparison with the rest of the UK shows any difference as soon as it appears. If the Senedd sets a band above or below 10p, that line will move away from zero by the exact yearly cost or saving.

Being a Welsh taxpayer is about where you live

If your only or main home is in Wales for more of the tax year than anywhere else in the UK, you are a Welsh taxpayer. Someone living in Wrexham and working in Chester pays the Welsh rates; someone living in Shrewsbury and working in Newtown does not.

HMRC applies this through your tax code, which starts with C. The code follows the address HMRC holds, so an out-of-date address is the usual reason the wrong rates are applied. Tell HMRC promptly if you move into or out of Wales.

If you have two homes, the deciding factor is where you spend most days in the tax year. Family, work patterns and second properties can make this less obvious than it sounds, and it is decided for the whole tax year, not month by month.

Using the results sensibly

The calculator gives a yearly estimate for one set of figures. It assumes your income is taxed through PAYE or Self Assessment in the normal way, and it does not model National Insurance, student loan repayments, the marriage allowance or Blind Person’s Allowance, or split a year in which you moved across the border.

Enter pension contributions and Gift Aid donations as gross amounts, since those reduce adjusted net income for the taper. Salary sacrifice lowers your gross pay before tax, so enter the reduced salary instead.

This is a planning estimate, not tax advice or a substitute for your HMRC calculation. Check your figures against your P60, payslips or Self Assessment return before acting, and take professional advice where the amounts are significant.

About This Tool: Welsh Income Tax

Welsh income tax: use this tool to get an instant, accurate estimate. The figures follow official GOV.UK guidance and every rate and threshold is kept up to date for 2026. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.