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Salary, Bonus and Pension Optimiser

A mobile-friendly UK compensation model for working out how much of a bonus should stay as taxable cash and how much should be routed as an employer pension contribution. The point is to avoid unnecessary threshold cliffs in tax and student loan deductions while still keeping enough cash now.

NFA / DYOR / E&OE

Not financial advice. Do your own research. Errors and omissions excepted. Treat this as an indicative planning tool and double-check the figures against your payslip, pension scheme rules, HMRC guidance and, where needed, a qualified adviser as best practice.

Next.jsReactTailwindUK tax modelling
What This Optimises
  • Cash bonus is treated as taxable pay, so income tax, employee NI and student loan can apply.
  • Bonus routed as an employer pension contribution is treated as outside taxable pay in this model.
  • The goal is to keep non-pension income out of new tax bands or student loan cliffs where possible.
  • Example inputs start at £98,000 salary with SMART at 5%.
  • Plan 1 is selected so the sample includes a visible student loan repayment.
  • With the current setup, that student loan is about £547 a month.

Scenario inputs

Salary, pension method and loan plan define which thresholds the cash part of the bonus can trip.

Pension method
Salary sacrifice lowers non-pension income directly, which can help keep the cash part of the bonus below key thresholds.
Student loan

Bonus setup

Cash bonus attracts tax, employee NI and possibly student loan. Employer pension routing does not.

Bonus input mode
Annual salary
£98,000
Loaded example matches the attached scenario
Bonus gross
£8,820
9% of salary
Monthly take-home
£5,053
Current scenario
Total pension added
£12,005
Employee plus employer
Threshold protection target
21.8%

Routing about 21.8% of the bonus to pension keeps non-pension income at or below £100,000 and helps avoid the personal allowance taper point.

Current setting
25%
Target threshold
£100,000
ANI now
£99,715
ANI if all bonus is cash
£101,920
Free Childcare / ANI

Working-parent free childcare support can be lost if expected adjusted net income goes above £100,000 for the current tax year.

Taking the bonus fully as cash would push adjusted net income above £100,000, which can mean losing working-parent free childcare support.

HICBC / ANI

High Income Child Benefit Charge starts above £60,000, reaches full clawback at £80,000, and tapers at 1% of Child Benefit for every £200 over the threshold.

Adjusted net income is already at or above the HICBC full-clawback point.

Threshold optimiser readout

Cash kept from the bonus
36.8%
£3,241 kept versus the all-pension baseline
All-cash deductions
55.4%
£4,882 lost to income tax, employee NI and student loan on the full cash bonus
Cash portion tax drag
51.0%
£3,374 lost on the bonus portion still kept as taxable cash
Matched employer contribution
£4,900
5% cap entered
What the recommendation is trying to avoid

Paying the whole bonus as cash would push non-pension income from £93,100 to £101,920, which crosses the personal allowance taper point. Routing about 21.8% of the bonus as an employer pension contribution keeps non-pension income at or below £100,000 while still leaving take-home around £60,771.

personal allowance taper point

Annual breakdown

Income tax
£27,318
Employee NI
£4,005
Student loan
£6,559
Benefits deduction
£1,200
Employee pension including bonus
£7,105
Employer pension including match
£4,900
Adjusted net income
£99,715
Personal allowance used
£12,570

Tax cost of the cash portion

This isolates the slice of the bonus you still take as taxable cash instead of sending all of it as an employer pension contribution.

Cash portion of bonus
£6,615
Gross amount still kept outside pension
Net cash you actually keep
£3,241
Incremental take-home versus sending the whole bonus to pension
Tax, NI and loan on cash portion
£3,374
51.0% lost on the part not sent to pension
If the same slice were sent as an employer pension contribution instead, this model treats it as avoiding income tax, employee NI and student loan deductions on that amount. The trade-off is lower take-home now in exchange for higher pension funding.

Scenario anchors

Baseline non-pension income
£93,100
Non-pension income if full bonus is cash
£101,920
All bonus as taxable cash
£61,329
All bonus as employer pension contribution
£57,392
Difference in take-home now
£3,938
Bonus routed as employer pension contribution
£2,205
Bonus still paid as taxable cash
£6,615

Allowance checks

Standard annual allowance
£60,000
Tapered annual allowance
£60,000
Threshold income for taper
£99,715
Adjusted income for taper
£111,720
No annual allowance breach is detected for the current inputs.

Rules hard-coded for 2026/27

Income tax
Personal allowance £12,570
20% basic up to £50,270
40% up to £125,140
45% above that
Allowance taper
Personal allowance starts tapering above £100,000 at a rate of 1 for every 2 over the threshold.
Employee NI
0% to £12,570
8% to £50,270
2% above that
Pension limits
Annual allowance £60,000
Minimum tapered allowance £10,000