A pay rise is the rare email everyone opens happily — until the first payslip arrives and the numbers feel… polite. UK Income Tax and National Insurance are marginal: extra salary is taxed at your top rate, not your average rate. Cross a band boundary and the bite gets sharper. This guide shows what actually lands in your account, with 2025/26 figures for England, Wales, and Northern Ireland.
The short answer: £45k → £55k
Moving from £45,000 to £55,000 gross (no pension, no student loan, standard tax code 1257L) adds about £545/month take-home — not the £833 you might expect from dividing £10,000 by 12.
At £45,000
£2,993/mo
~£35,916/year net
At £55,000
£3,538/mo
~£42,456/year net
That is roughly 65% of the raise landing in your pocket (~£6,540 extra per year). The rest goes to Income Tax and employee NI. HMRC essentially RSVPed yes to your promotion.
Why the raise feels smaller than advertised
Three forces eat the gap between gross and net on a £10k uplift:
- Marginal Income Tax — the slice of your raise above £50,270 is taxed at 40% (higher rate), not 20%
- National Insurance — 8% on earnings £12,571–£50,270 and 2% above, for 2025/26 employees
- Band straddling — at £45k you were mostly basic rate; at £55k a chunk of income sits in higher rate permanently
Your average tax rate might be ~29% at £55k, but the marginal rate on the last few thousand can approach 48% (40% tax + 8% NI) before student loans.
Breaking down the £10k raise
Rough annual breakdown of the uplift from £45k to £55k:
About £5,270 of the raise sits entirely above the higher-rate threshold, attracting 40% tax plus 2% NI on that portion — the expensive slice.
Smaller raises matter too
Not every uplift is £10k. A £3,000 rise from £42k to £45k stays mostly in basic rate:
- Marginal hit ≈ 20% tax + 8% NI = 28% on most of the raise
- Extra take-home ≈ £2,160/year (~£180/month) — about 72% kept
A £5,000 rise from £48k to £53k straddles £50,270, so the effective keep-rate drops toward 60–65%. Job-offer comparisons should always use your current salary as the baseline, not round numbers from LinkedIn.
Student loan trims the celebration
On Plan 2 (threshold £29,385 in 2025/26), a pay rise triggers an extra 9% on income above the threshold. A £10k rise from £45k to £55k adds roughly £900/year loan repayment (~£75/month) on top of tax and NI. See our student loan guide for plan-by-plan maths.
Pension sacrifice changes the picture
If you sacrifice salary into a pension, the raise might be calculated on pre- or post-sacrifice pay depending on HR. Sacrifice reduces Income Tax and NI on the amount given up — a £55k earner putting 5% in might see a different marginal rate on the cash raise. Our pension sacrifice guide shows how 5% on £50k costs ~£150/month take-home but puts ~£208 in the pot.
Scotland: same NI, different tax
Scottish Income Tax uses more bands (starter, basic, intermediate, higher, advanced). A £45k → £55k move in Scotland may yield a different net than England — often slightly less at middle incomes. Compare regions in our Scotland vs England guide or flip the Region toggle in TaxBite.
The £100k trap on big promotions
If a raise pushes you from £95k to £105k, you enter personal allowance taper territory. For every £2 earned above £100k, you lose £1 of tax-free allowance — an effective 60% marginal rate on some income when combined with 40% tax and 2% NI. Big promotions deserve a calculator, not gut feel.
Inflation and “real” raises
A 3% uplift on £45k is £1,350 gross — roughly £80–£95/month net if you stay in basic rate. If inflation is 4%, your purchasing power still shrinks even with a “raise”. Gross percentage announcements from HR need net context to mean anything.
Benefits that change the raise
- Car allowance / company car — taxable benefit can eat part of a headline rise
- Private medical — BIK tax applies; still valuable, but not cash
- Share schemes — RSUs and options have their own tax timing (not modelled here)
- Cycle to work / childcare vouchers — salary sacrifice can boost effective value
Job offer maths — compare take-home, not gross
Always model net monthly pay. A £5k higher offer might only be £160–£250/month after tax depending on where you sit in the bands. Benefits (bonus, pension match, hybrid days) belong in the spreadsheet too — but gross salary alone misleads.
TaxBite shows the bite before you sign. Enter your current salary, then your offer, and compare monthly net side by side. Use our salary tables to sanity-check round numbers.
Compare £45k vs your offer →£55k take-home page → · Bonus tax →
Estimates only — not tax advice. Tax codes, benefits-in-kind, and payroll timing change real payslips. Rates: gov.uk.