How pension salary sacrifice works in the UK
Pension salary sacrifice, also known as salary exchange, is an arrangement between you and your employer where you agree to reduce your contractual gross salary by an agreed amount. In exchange, your employer pays an equivalent contribution directly into your workplace pension scheme.
Because the pension contribution is made before your pay is calculated, your official gross salary is lower. This reduces the amount of Income Tax you pay (at 20%, 40%, or 45%, or Scottish rates) and also reduces your Class 1 employee National Insurance contributions (currently 8% in the basic rate band and 2% in the higher rate band).
If you are repaying a student loan under Plan 1, Plan 2, Plan 4, Plan 5, or a Postgraduate Loan, salary sacrifice also reduces your student loan repayments because deductions are calculated from your post-sacrifice gross salary above the applicable repayment threshold.
Employers also save on Class 1 Secondary National Insurance on the sacrificed amount. Many progressive employers choose to pass some or all of their National Insurance savings back to the employee by adding it as an extra top-up to the pension pot.
UK employment law requires that salary sacrifice cannot reduce your contractual earnings below the statutory National Minimum Wage or National Living Wage rate for your age. Your employer will review your earnings before approving a salary sacrifice agreement.
Worked example: £40,000 salary with £2,000 pension sacrifice
Consider an employee in England earning a gross annual salary of £40,000 during the 2026-27 tax year who agrees to sacrifice £2,000 per year into their workplace pension scheme.
Without salary sacrifice, an annual salary of £40,000 yields take-home pay of £32,319.60 per year after Income Tax and employee National Insurance.
With a £2,000 salary sacrifice, the employee's contractual gross salary becomes £38,000. Their revised take-home pay is £30,879.60 per year, representing a net reduction in take-home pay of £1,440.00 per year or £120.00 per month.
The £2,000 pension contribution generates £400.00 in Income Tax savings (20% of £2,000) and £160.00 in National Insurance savings (8% of £2,000). While the full £2,000 goes into the employee's pension fund, it costs the worker only £1,440.00 in net pay, delivering an immediate £560.00 tax advantage.
Inputs for the salary sacrifice pension calculator
Tax year
The UK tax year for the calculation, determining the Personal Allowance, income tax bands, and National Insurance thresholds.
Gross salary before sacrifice (per year)
Your current annual gross salary before tax and before applying any pension salary sacrifice agreement.
Pension salary sacrifice (per year)
The annual gross amount you agree to sacrifice and redirect into your workplace pension scheme.
Where you pay income tax
Select Scotland if you are a Scottish resident for tax purposes, as Scottish income tax rates and bands apply.
Student loan
Your UK student loan plan. Salary sacrifice reduces your gross pay, lowering your annual student loan repayment amount.
Postgraduate Loan
Select yes if you have an active UK Postgraduate Master's or Doctoral loan from the Student Loans Company.
CALCULATOR QUESTIONS
Salary sacrifice pension calculator questions
What is the difference between salary sacrifice and relief at source pensions?
With relief at source, pension contributions are deducted from your net pay after tax, and the pension provider reclaims basic rate tax (20%) from HMRC. Under salary sacrifice, your gross salary is lowered before payroll calculations, meaning you save both Income Tax and National Insurance immediately.
Does salary sacrifice pension affect my state pension?
As long as your salary after sacrifice remains at or above the National Insurance Lower Earnings Limit, your qualifying years for the UK State Pension are fully protected.
Can salary sacrifice affect mortgage applications?
Most mortgage lenders understand salary sacrifice schemes and will consider your pre-sacrifice gross salary when assessing mortgage affordability, especially if supported by an employer reference.
Can I opt out of salary sacrifice pension?
Yes. Salary sacrifice is a contractual variation, and employers allow employees to opt out or change contribution amounts either annually during benefits renewal or upon a qualifying lifestyle event such as marriage, maternity, or redundancy.