London HCAS Explained for NHS Staff

What HCAS actually is

If you work for the NHS in London, your contract may mention a High Cost Area Supplement. Most people still call it London weighting. It is an extra payment on top of Agenda for Change basic salary for staff whose workplace sits in a designated high-cost area.

The national rules sit in the NHS Terms and Conditions of Service Handbook. Annex 8 covers the payment zones and Annex 9 covers the supplement itself. NHS Employers also publishes the 2026/27 pay scales inclusive of HCAS.

Scotland, Wales and Northern Ireland do not use the Inner / Outer / Fringe HCAS system on the national AfC scale. If you are comparing a London job with a post elsewhere in the UK, strip HCAS out of the England figure or you are not comparing like with like.

Inner, Outer and Fringe rates for 2026/27

There are three standard zones. The percentages most staff will recognise are 20% Inner London, 15% Outer London and 5% Fringe. Those percentages are not open-ended: each zone also has a minimum and maximum cash amount for the year.

For 2026/27, NHSBSA’s employer guidance summarises the caps as Inner London 20% (minimum £5,794, maximum £8,746), Outer London 15% (minimum £4,870, maximum £6,137) and Fringe 5% (minimum £1,346, maximum £2,270). See the High Cost Area allowance note. NHS Employers confirmed the Annex 9 minima and maxima were uplifted from 1 April 2026 in its 2026 pay and TCS advisory notices.

Which zone you get is about where you work, not where you live. Your offer letter, contract or ESR assignment should name the zone. If it only says “London weighting”, ask HR or payroll to confirm Inner, Outer or Fringe.

What it does to take-home pay

HCAS increases gross pay, so income tax and employee National Insurance usually rise as well. NHS pension contributions are tiered on pensionable pay, so a London uplift can move you into a higher contribution percentage even if your band has not changed. Member rates and tiers are published by NHSBSA and NHS Employers.

You still take more home in most cases, but not the full gross uplift. That is why “basic plus HCAS” on a job advert is only half the story.

On this site, open any England band calculator, set your pay point and hours, then choose Inner, Outer or Fringe from the High Cost Area dropdown. The results panel shows basic, HCAS and estimated net pay after tax, NI, pension and student loans.

One trap when reading Section 2 unsocial pay

Unsocial hours enhancements are calculated on basic salary. Under Section 2 of the handbook, they do not include HCAS. NHS Employers’ summary of unsocial hours payments is clear on that point. So a busy Inner London rota is not “HCAS × night percentage” stacked on the same hour.