The Short Answer

Salary sacrifice (sometimes called salary exchange) is an arrangement where you give up part of your salary in exchange for a larger employer pension contribution. You pay less income tax and National Insurance. Your employer pays less National Insurance too — and good employers pass that saving into your pension.

How It Works

Here is an example. You earn £50,000. You sacrifice £5,000 of salary. Your gross pay drops to £45,000. But your employer puts the full £5,000 (plus their National Insurance saving) into your pension. You save 20–40% income tax plus 12% National Insurance on the sacrificed amount.

Without salary sacrifice

  • Gross salary: £50,000
  • You contribute £5,000 from net pay
  • You still pay National Insurance on £50,000

With salary sacrifice

  • Gross salary: £45,000
  • Employer contributes £5,000+ to pension
  • You pay National Insurance on £45,000 only

The Benefits

  • More goes into your pension for the same cost to you.
  • Lower National Insurance contributions for you and your employer.
  • Reduces your taxable income — helpful near tax band boundaries.
  • Especially powerful for higher-rate taxpayers who save 40% income tax plus National Insurance.

The Risks

A lower gross salary could affect:

  • Mortgage applications — lenders use gross salary to assess affordability.
  • Statutory sick pay and maternity or paternity pay — both based on gross earnings.
  • Life insurance — if your employer scheme is based on salary.
  • No guarantee of employer savings — your employer is not obligated to pass on their National Insurance saving.

Who Should Consider It?

  • Higher and additional rate taxpayers get the biggest benefit.
  • Anyone whose employer passes on the National Insurance saving.
  • People not planning to apply for a mortgage soon.