Part-time · 20 hrs/wk

Cost of employing someone 20 hours a week (2025/26)

A 20-hour-per-week employee working at the National Living Wage (£12.21/hour) earns approximately £12,698 per year. The employer NI secondary threshold of £5,000 is not reduced for part-time hours, so employer NI applies on £7,698 at 15% — adding approximately £1,155 per year. Minimum pension adds a further £194 on qualifying earnings above £6,240. Total statutory employer cost above salary: approximately £1,349 per year. Use the calculator for any salary.

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

Sample total cost

£14,046

£1,171 per month on £12,698 salary

Employer NI

£1,155

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

Pension + overheads

£194

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

Use the live tools

Calculate exact employer cost Part-time employee cost overview 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 employers pay NI on 20-hour part-time workers?
Yes, if annual earnings exceed the £5,000 secondary threshold. At 20 hours per week on the National Living Wage, annual salary is approximately £12,698, which is above the threshold. Employer NI at 15% applies on earnings above £5,000, regardless of whether the employee is part-time or full-time. The threshold is not pro-rated for contracted hours.
Does auto-enrolment apply to part-time employees?
Auto-enrolment triggers when a worker earns more than £10,000 per year and is aged 22–66. Part-time workers earning below £10,000 per year do not need to be automatically enrolled but can opt in, in which case the employer must still make contributions. Workers earning between £6,240 and £10,000 can opt in and the employer must contribute at the minimum rate on qualifying earnings.
Is it cheaper to employ someone part-time than full-time per hour?
The gross wage cost per hour is identical for part-time and full-time staff on the same hourly rate. However, the employer NI secondary threshold (£5,000/year) is not reduced for part-time hours. This means the NI cost as a percentage of gross salary is higher for lower-paid part-time workers than for higher-earning full-time staff. For very low-hour workers earning below £5,000/year, there is no employer NI at all.
What is the National Living Wage from April 2025?
The National Living Wage for workers aged 21 and over is £12.21 per hour from April 2025, rising from £11.44 per hour in 2024/25. The National Minimum Wage for workers aged 18–20 is £10.00 per hour.

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