Enter three useful figures
- Employment income
- Planned salary sacrifice
- Employer pension contribution
Free UK calculator · 2026/27
See what the £100k tax trap could mean for your pay and pension.
Compare adjusted net income, estimated take-home pay and pension funding before changing salary sacrifice.
See the trade-off
- Adjusted net income estimate
- Take-home pay before and after
- Total pension funding
- Take-home cost of the change
Keep the result
Deliberately save a scenario on this browser or prepare a portable report. No login is required and nothing is saved automatically.
Worked illustration
A £110,000 salary does not automatically mean a £10,000 answer.
If £110,000 were your complete adjusted-net-income estimate before a proposed change, a £10,000 gross gap would bring the illustration to £100,000. But taxable benefits, a bonus, savings interest, dividends or rental income can increase the gap. Existing pension contributions and Gift Aid can reduce it.
The calculator therefore shows an employment-income scenario, not a complete Self Assessment calculation. HMRC defines adjusted net income using total taxable income less specified reliefs.
Check HMRC’s adjusted-net-income guidance.
Three checks before changing payroll
- Confirm the income figure, contribution basis and election deadline with payroll.
- Combine employer and personal pension input across every scheme before checking annual allowance, tapering, carry forward or the Money Purchase Annual Allowance.
- Check whether statutory pay, mortgage affordability or employer benefits use pre- or post-sacrifice salary.
Salary sacrifice changes contractual cash pay and requires employer agreement. It cannot reduce cash earnings below the applicable National Minimum Wage. Pension inputs can also create a tax charge if they exceed the allowance available to you.