Part-time cost

Part-time employee cost UK (2025/26)

Part-time employees carry most of the same employer cost obligations as full-time staff. Employer NI at 15% applies on earnings above £5,000 regardless of hours — the threshold is not pro-rated. Auto-enrolment pension applies if the part-time employee earns more than £10,000 per year with you and is the right age. This page sets out the true recurring cost of part-time employees at common salary levels for 2025/26.

UK scope: England, Scotland, Wales and Northern Ireland employer payroll planning for the 2025/26 tax year.

Sample total cost

£43,363

£3,614 per month on £35,000 salary

Employer NI

£4,500

15% above £5,000 secondary threshold (2025/26)

Pension + overheads

£3,863

Baseline employer pension plus configured overheads

Key assumptions — UK 2025/26

Employer NI: 15% on earnings above the £5,000 secondary threshold

Employer pension: minimum 3% on qualifying earnings £6,240–£50,270

Employment Allowance: up to £10,500 off the NI bill for eligible employers

Worked examples: £30k salary → £34,464/yr · £35k → £40,363/yr · £50k → £58,063/yr

What this page helps you check

Employer NI threshold of £5,000 is fixed — not reduced for part-time hours.
Auto-enrolment applies above £10,000 earnings in a single job.
At £15,000 part-time salary: NI = £1,500/yr, pension = £262/yr. Total ≈ £16,762/yr.
At £20,000 part-time salary: NI = £2,250/yr, pension = £411/yr. Total ≈ £22,661/yr.
Employment Allowance applies to part-time employees the same as full-time.

Use the live tools

Calculate part-time employee cost Read the full guide Cost of employing by salary Employer NI by salary Auto-enrolment pension calculator

UK assumptions used

Employer NI

15% above £5,000 secondary threshold for 2025/26.

Auto-enrolment pension

Minimum employer contribution 3% on qualifying earnings.

Employment Allowance

Up to £10,500 relief in 2025/26 for eligible employers.

Official UK references

HMRC rates and thresholds Employment Allowance Pensions Regulator guidance Our methodology Our source list

Frequently asked questions

Do I pay employer NI on part-time employees?

Yes. The £5,000 secondary threshold is not pro-rated for part-time hours. Employer NI at 15% applies to all earnings above £5,000 regardless of how many hours the employee works. A part-time worker earning £15,000 per year generates £1,500 in employer NI.

Do I need to auto-enrol a part-time worker?

You must auto-enrol if the worker earns more than £10,000 per year from you, is aged 22 to State Pension Age, and works in the UK. If they earn between £6,240 and £10,000, they can opt in but you do not have to enrol them automatically. Below £6,240, no pension obligation applies.

How much does a part-time employee on £16,000 cost?

At £16,000 salary in 2025/26: employer NI is £1,650 per year (15% of £11,000). Pension qualifying earnings are £16,000 − £6,240 = £9,760; minimum employer contribution is £292.80 per year. Total employer cost before overheads: approximately £17,943 per year.

UK coverage only. Last reviewed: 04 April 2026. Estimates use 2025/26 assumptions and are for planning, not legal or tax advice.