What Salary Sacrifice Is
NHS salary sacrifice is a deal with your employer: you give up part of your gross Agenda for Change pay and they put it into a scheme instead (extra pension, an EV lease or cycle to work). The key word is “gross”: the money leaves your pay before tax, National Insurance or student loan are worked out, which is why it changes more than your income tax.
This is not the same as a NET pay pension, which lowers your taxable income but not your NI. And it is not the same as relief at source, where pension comes out after tax and your provider claims back basic-rate tax for you.
Which NHS Schemes You Can Sacrifice Into
One thing to be clear on first: the main NHS Pension Scheme is not a salary sacrifice arrangement. It runs on NET pay, so your contribution comes off your gross before income tax and you get tax relief automatically, but National Insurance is still charged on your full pay. You cannot sacrifice salary into the main scheme.
What you can sacrifice is whatever your employer offers, and trusts and boards each run their own list. The common ones are:
- Cycle to work: a bike and kit paid for out of pre-tax salary, spread over a year or so.
- Electric car lease: a growing number of trusts offer an EV salary sacrifice scheme, where the lease comes off your gross pay.
- Home and lifestyle benefits: some employers add home technology, gym membership or similar through a benefits provider.
Each of these comes off your gross before HMRC works out your tax and National Insurance, so it lowers both your NI and student loan the same way the worked example below shows. What is on offer, and whether salary sacrifice is available at all, depends on your employer, so check your trust’s benefits portal or ask HR.
Why It Changes Everything
Because the sacrifice happens before tax, it lowers the number used for every step after it. Your NI drops. Your student loan drops. Your adjusted net income drops.
Say a senior manager earns £135,000 and sacrifices £20,000. Their gross for NI and student loan becomes £115,000, not £135,000. That one change can cut their NI by hundreds and their student loan by nearly £2,000 a year.
It also matters if you earn above £100,000. You lose £1 of tax-free allowance for every £2 over that mark. A big enough sacrifice can bring you back below the line and restore your full £12,570 allowance.
Where Calculators Go Wrong
We tested seven UK take-home pay calculators against a salary sacrifice scenario. Three had no salary sacrifice input at all. Of the four that did, results still differed by up to £1,883 on the student loan line alone.
The root cause is ordering. If a tool takes off pension after NI and student loan, it shows too much for both. If it only takes a percentage and not a fixed pound amount, rounding errors creep in. HMRC’s own tool has this problem. It only takes a pension percentage, so £20,000 has to be entered as 14.81%, which shifts the numbers.
Use a tool that skips salary sacrifice and enter a normal pension instead? Your take-home figure could be wrong by thousands of pounds a year.
The Numbers
We ran £135,000 gross with a £20,000 salary sacrifice pension and a Plan 2 student loan through all seven tools. Tax matched at £36,432 across every tool that supports salary sacrifice, but NI ranged from £4,310 to £4,711 and student loan from £7,704 to £9,588, a £1,884 gap on student loan alone.
See the full results table in the UK calculator comparison.
Check Your Own Numbers
The Casomo take-home pay calculator supports salary sacrifice as a fixed pound amount. Enter your gross salary and pension to see how NI, student loan, and take-home pay change.