Salary sacrifice pensions and take-home pay
Last updated: 18 October 2026
How a 2026/27 salary-sacrifice pension changes tax and National Insurance, with a worked £48,000 example, and why the £2,000 cap waits until 2029.
What you give up
A salary sacrifice for a pension is a change to the contract. You agree to a lower salary. The employer pays the difference into the pension. GOV.UK’s salary-sacrifice guidance explains that the lower salary is the figure PAYE uses. Tax, employee National Insurance and student loan deductions that follow gross pay for Class 1 National Insurance are all calculated on that lower figure.
That is different from a relief-at-source scheme, where you contribute from pay that has already been taxed and the provider claims 20% from HMRC. It is also different from a net-pay arrangement, which reduces taxable pay but does not, by itself, reduce National Insurance. The take-home calculator asks which of the three you have, because the payslip is different in each case.
How it's calculated
For 2026/27 the employee National Insurance main rate is 8% and the rate above the upper earnings limit is 2%. Income Tax uses the Personal Allowance of £12,570 and the rest-of-UK or Scottish bands. A sacrifice is deducted from gross salary before those calculations. The pension pot is credited with the amount sacrificed. Extra employer contributions, if any, are a matter for the contract and are not invented here.
Student loan deductions use the same gross as employer Class 1 National Insurance when the payroll rules say so. A sacrifice therefore lowers the earnings the loan percentage sees. A net-pay or relief-at-source contribution does not. The calculator follows that split. Weekly and monthly loan deductions are rounded down to a pound.
Worked examples
Take a salary of £48,000 in England, Wales or Northern Ireland, with no student loan. With no pension, income tax is £7,086.00, National Insurance is £2,834.40, and take-home pay is £38,079.60.
Sacrifice 5%, which is £2,400.00. Income tax falls to £6,606.00. National Insurance falls to £2,642.40. Take-home pay is £36,351.60. The cash in the bank is lower than the no-pension figure because £2,400 has gone into the pension, but tax and National Insurance are both lower than they were on the full £48,000. That National Insurance saving is the part a relief-at-source contribution does not give you.
On a lower salary of £30,000 with no pension, tax is £3,486.00 and National Insurance is £1,394.40. A sacrifice on that salary still reduces both, but the pounds saved are smaller because less of the contribution sits in a taxed band. Run your own percentage on the take-home page rather than scaling the £48,000 example by guesswork.
The 2029 cap, and what this page leaves out
GOV.UK has published a reform that, from 6 April 2029, charges Class 1 National Insurance on salary-sacrifice pension contributions above £2,000 a year. That rule is not in force for 2026/27. The calculator does not apply it. If you are comparing a job offer for a later year, do not treat a 2026/27 illustration as the National Insurance position after April 2029.
The annual allowance, and the taper of that allowance for high incomes, can create a tax charge on pension savings. Those figures are not in the rate file, because I have not put an annual-allowance calculator on the site. A sacrifice that looks kind on a monthly payslip can still be a problem against the annual allowance. This page will not reassure you about that.
Sacrifice can also affect statutory pay, borrowing tests that use contractual salary, and some benefits that are a percentage of salary. Those are employment questions, not a line in the income tax bands. I update the rate file after each Budget and when HMRC changes a threshold. The numbers above are produced by the same function as the calculator, so they move if the rate file moves.
What a payslip should show
Read the payslip in three places. The contractual salary is the figure you agreed. After a sacrifice the taxable gross and the National Insurance gross are the lower figure. The pension line should show the amount that left your pay. If the employer adds a contribution of their own, that extra is not part of the percentage in the worked example above. I do not know your contract, so I do not add an employer top-up.
National Insurance is not devolved. A sacrifice in Scotland reduces the earnings that employee Class 1 National Insurance sees in the same way as in England, Wales and Northern Ireland. Income Tax then uses the Scottish bands on what remains. The take-home page has a Scotland switch for that reason. Do not take the England tax figure from the £48,000 example and apply it to a Scottish salary.
A sacrifice can also change the £100,000 Personal Allowance taper, because it reduces the income that taper looks at. The separate guide on the band between £100,000 and £125,140 walks through employment income with no pension. If a sacrifice pulls adjusted net income back towards £100,000, some of the lost allowance comes back. That is a different sum from the National Insurance saving, and it only matters once income is in that band.
I still do not calculate the annual allowance. To do it properly I would need the pension input amount for this year and the unused allowance from the earlier years, and I do not ask for those. A contribution that looks modest on one month’s payslip can be large once the employer’s payment and a bonus sacrifice are added. If you are near that limit, the conversation is with the scheme and with HMRC, not with this page.
Questions
Does salary sacrifice reduce National Insurance?
Yes. The sacrificed amount is no longer salary, so employee and employer Class 1 National Insurance are worked out on the lower figure. That is the PAYE effect GOV.UK describes.
Is the £2,000 National Insurance cap in force?
Not for 2026/27. GOV.UK says contributions above £2,000 a year are due Class 1 National Insurance from 6 April 2029. This site does not apply that cap.
Does relief at source work the same way?
No. You pay the contribution from after-tax pay. The scheme claims basic-rate relief. It does not reduce National Insurance or student-loan pay the way a sacrifice does.
Does this page check the annual allowance?
No. The annual allowance and the tapered annual allowance are not applied. A large contribution can create a charge this calculator will not show.