Hiring an admin assistant in the UK in 2026 costs £30,000–£42,000 per year fully-loaded — not the £24k headline salary HR quotes. Here is the full breakdown, plus what AI alternatives now cost.
Headline salary
£24k–£30k
Fully-loaded
£32k–£42k
Hidden uplift
+30–40%
AI equivalent
£8k–£15k/yr
Most UK admin assistant job ads quote £24,000–£30,000. That number ignores employer National Insurance (currently 13.8% above £9,100), pension auto-enrolment (3% minimum), holiday pay, sick days, and the management overhead of having a person in a seat.
When you add it all up, the true annual cost of an admin hire in the UK in 2026 sits between £32,000 and £42,000 depending on location and seniority.
Employer NICs alone add roughly £2,500–£3,000 on a £25k salary. Pension contributions add another £750+. Software licences (Microsoft 365, CRM seat, helpdesk) cost £600–£1,200. Recruitment and onboarding amortise to £1,500–£3,000 per year. Sick days and holiday cover add 8–10% effective wage.
AI agents that handle 60–80% of admin tasks now cost £8,000–£15,000 per year all-in. That includes build cost amortised over year one and ongoing inference. The gap is so wide that hiring without first quantifying AI alternatives is a fiduciary mistake.
| Cost line | Junior | Mid |
|---|---|---|
| Salary | £24,000 | £30,000 |
| Employer NICs (13.8%) | £2,055 | £2,883 |
| Pension (3%) | £720 | £900 |
| Software seats | £720 | £1,200 |
| Recruitment (amortised) | £1,500 | £2,500 |
| Holiday + sick cover | £2,400 | £3,000 |
| Equipment + space | £1,200 | £1,800 |
| Total fully-loaded | £32,595 | £42,283 |
Mid figures assume London/SE. Outside London, deduct ~£3,000 across salary and ancillary costs.
Temp admin via agency runs £18–£28/hr. On 35 hrs/wk it equates to £33,000–£51,000/yr — typically more expensive than permanent.
For repetitive admin (data entry, scheduling, document handling), yes. For judgement-heavy work, AI augments rather than replaces — typically a 50/50 hybrid.