Pension Salary Sacrifice Calculator UK (2026)

With salary sacrifice (also called smart pensions), you agree to contractual salary reduction in exchange for your employer paying an equivalent contribution directly into your pension scheme. Because your gross salary is lower, you pay less income tax and less employee National Insurance.

Under personal relief-at-source pensions, basic rate income tax (20%) is claimed back into your pot, but employee NI is still deducted. Salary sacrifice reduces your gross pay before payroll, exempting that money from both income tax AND employee National Insurance (8% basic rate or 2% higher rate).

Earnings between £100,000 and £125,140 lose £1 of Personal Allowance for every £2 earned, creating a brutal 60% income tax rate (+2% NI = 62%). Sacrificing salary above £100,000 back down to £100,000 restores your full £12,570 Personal Allowance, giving an instant 62% return on investment.

No. By UK employment law, a salary sacrifice arrangement cannot reduce an employee cash earnings below the National Minimum Wage or National Living Wage rate.

When you sacrifice salary, your employer saves 15% employer Class 1 National Insurance. Many progressive employers pass 50% to 100% of this NI saving directly into your pension pot as a bonus top-up!