Salary sacrifice: the pension trick hiding in plain sight

Salary sacrifice (sometimes called "salary exchange") is an arrangement where you agree to reduce your salary, and your employer pays the amount you gave up into your pension instead.

Why bother? National Insurance.

The maths

With a normal pension contribution, you pay National Insurance on your full salary and then contribute from what's left (with tax relief added back). With salary sacrifice, the money goes into your pension before NI is calculated — so neither you nor your employer pays NI on it.

For a basic rate taxpayer, that's an extra 8% saving on top of the usual tax relief. Some employers even pass on part or all of their own employer NI saving (13.8%) as an extra pension contribution — turning a good deal into an excellent one.

The result: for the same reduction in take-home pay, more money lands in your pension. There aren't many genuine free lunches in personal finance; this is close to one.

Bonus sacrifice

The same logic applies to bonuses, often with even bigger effect. Sacrificing a bonus straight into your pension avoids income tax and NI on it entirely at the point of payment — particularly powerful for higher earners, and doubly so for anyone in the 60% effective tax band between £100,000 and £125,140 (see our article on the 60% tax trap).

The catches

A lower official salary can affect anything calculated from it: mortgage affordability assessments, statutory maternity/paternity pay, life cover through work, and some benefits. Your salary also can't drop below the National Minimum Wage through sacrifice.

For most people most of the time, the catches are manageable and the NI saving wins. But if you're about to apply for a mortgage or start a family, check the knock-on effects first.

Worth knowing: the government has announced plans to cap the NI advantages of pension salary sacrifice from 2029, with amounts sacrificed above £2,000 a year becoming subject to NI. The benefit remains fully intact until then, and even after, the underlying tax relief on pensions is unaffected — but it's a reminder that using generous rules while they exist is rarely a mistake.

This article is for general education only and isn't personal advice. Check whether your employer offers salary sacrifice — many do without employees ever using it.