Taxable Income
The portion of your total income that is actually subject to income tax after deducting the Personal Allowance and any other reliefs or deductions you are entitled to. It is calculated by taking your gross income from all sources, subtracting the Personal Allowance and any allowable reliefs, and then applying the tax bands to what remains. Pension contributions, Gift Aid donations, and trading losses can all reduce your taxable income.
How it works
Taxable income is calculated after your Personal Allowance and certain reliefs are deducted from your gross income, which means it's almost always a smaller figure than your salary or total earnings. It's this reduced figure, not your gross pay, that gets run through the tax bands to work out how much tax you actually owe.
Several common actions reduce taxable income before the bands are applied: pension contributions made through relief-at-source or salary sacrifice, Gift Aid donations, which are grossed up for tax purposes, and trading losses carried forward by the self-employed. Because reducing taxable income can also help someone avoid crossing into a higher tax band or losing part of their Personal Allowance, these reliefs are frequently used deliberately for tax planning near a band threshold.
It's easy to confuse taxable income with total income or with 'adjusted net income', a related but distinct figure used specifically to test eligibility for things like the Personal Allowance taper and Child Benefit charge. The differences mainly relate to which reliefs are added back in for each specific test, so the same person can have different figures depending on which calculation HMRC is running.
Example: taxable income and tax due on a £45,000 salary
A salary of £45,000 minus the £12,570 Personal Allowance leaves taxable income of £32,430. This falls entirely within the Basic Rate band, up to £37,700 of taxable income, so it's all taxed at 20%.
Tax due is £32,430 × 20% = £6,486. Note that the Personal Allowance itself is never taxed — it's only the £32,430 of taxable income remaining after the allowance that's run through the bands.
Frequently asked questions
Is taxable income the same as my salary?
No — taxable income is your gross income after subtracting your Personal Allowance and any reliefs you're entitled to, so it's typically lower than your headline salary figure.
Do pension contributions reduce my taxable income?
Yes, in most cases — contributions made via salary sacrifice reduce your gross pay before tax is calculated, while relief-at-source contributions are topped up separately, but both routes ultimately lower the income that's actually taxed.
Why might HMRC use a different 'adjusted net income' figure instead of my taxable income?
Adjusted net income is a separate calculation used specifically for tests like the Personal Allowance taper, and it adds back certain reliefs in a different way, so it can differ from the taxable income figure used to work out your basic tax bill.
Related Terms
Personal Allowance
The amount of income you can earn in a tax year before paying income tax, currently £12,570 and frozen until April 2031 (the freeze was extended by three years at the Autumn Budget 2025).
Tax Bands
The ranges of taxable income to which different income tax rates apply, creating the UK's progressive tax system.
Effective Rate
The average rate of tax you pay across all your income, calculated by dividing your total tax bill by your gross income.
Marginal Rate
The rate of tax paid on the next pound of income you earn, which determines the tax cost or saving of earning slightly more or less.
Self Assessment
The system by which individuals report their own income, gains, and reliefs to HMRC each year through an online or paper tax return, rather than having tax collected automatically under PAYE.
Try the calculator
Use our free tool to see how taxable income affects your tax.