How salary sacrifice pension saves you tax — a real example

When setting up a workplace pension, the terminology can be confusing. The most financially efficient way to contribute to a pension in the UK is through an arrangement known as "Salary Sacrifice" (sometimes called Salary Exchange). If your employer offers this, you should almost always say yes. Here is a comprehensive breakdown of how salary sacrifice saves you hundreds of pounds in tax every year compared to standard pension contributions.

What is Salary Sacrifice?

Under a normal pension scheme (like "Relief at Source"), you receive your gross salary, pay Income Tax and National Insurance on it, and then a percentage of your post-tax money is paid into your pension. The government then adds 20% tax relief into the pension pot.

Salary Sacrifice works completely differently. You agree to legally give up (sacrifice) a portion of your gross salary before any tax is calculated. In return, your employer pays that exact same amount directly into your pension pot as an employer contribution.

The Double Tax Saving

Because your official gross salary has been lowered by the sacrificed amount, the amount of income subject to tax is lower. This creates two massive benefits:

1. Income Tax Savings: You do not pay any Income Tax on the money you sacrificed into the pension. This is immediate, at-source tax relief, completely bypassing the need to claim it back later.
2. National Insurance Savings (The Golden Ticket): This is the crucial advantage. With normal pension contributions, you still pay National Insurance on the money that goes into your pension. Under Salary Sacrifice, because the money is given up before taxation, you do not pay National Insurance on your pension contributions. For a basic rate taxpayer in 2026, this instantly saves you 8% on every pound you contribute.

Real-World Example (£30,000 Salary)

Let's look at an employee earning £30,000 a year, contributing 5% (£1,500 a year) to their pension, comparing the two methods.

• Without Salary Sacrifice (Net Pay Arrangement): You pay £3,486 in Income Tax and £1,394 in National Insurance. Your take-home pay is £23,620.
• With Salary Sacrifice: Your official salary becomes £28,500. You pay £3,186 in Income Tax and £1,274 in National Insurance. Your take-home pay is £24,040.

By using Salary Sacrifice, you have exactly the same amount of money going into your pension (£1,500), but your take-home pay has increased by £420 a year. This is entirely due to the National Insurance savings.

The Employer Benefit

It is not just you who saves money. Your employer also saves on Employer National Insurance contributions (usually 13.8% or 15%) because your gross salary is lower. Some highly generous employers will actually take the 15% they just saved and pay it into your pension pot as a bonus, supercharging your retirement fund at zero cost to themselves.

Are There Any Downsides?

Because Salary Sacrifice legally reduces your gross salary, it can impact calculations that rely on your headline pay:

• Mortgage Applications: Most modern lenders understand salary sacrifice and will calculate affordability based on your original salary, but some strict lenders might look at the lower post-sacrifice figure.
• Maternity/Paternity Pay: Statutory maternity pay is calculated based on your average earnings in a specific window. A lower gross salary means slightly lower statutory maternity pay.
• Life Insurance: If you have a death-in-service benefit (e.g., 4x your salary), check with your HR department if it is calculated on your pre-sacrifice or post-sacrifice salary.