If you work for the NHS in or around London, you are entitled to an additional payment on top of your standard Agenda for Change (AfC) salary. Officially known as the High Cost Area Supplement (HCAS), this is what most people still refer to as NHS London weighting. The supplement exists to help NHS staff cope with the significantly higher cost of living in and around the capital, covering everything from housing to commuting costs. Understanding exactly how HCAS affects your NHS take home pay in London is essential for budgeting and financial planning.
The supplement is divided into three geographic zones, each with a different annual payment added directly on top of your national AfC band salary. Whether you work in a central London hospital or in a town on the commuter belt, you will fall into one of these three categories.
Your HCAS entitlement depends entirely on where your workplace is located, not where you live. The three zones and their 2025/26 annual supplement values are:
Inner London covers the central boroughs such as Westminster, Camden, Islington, Tower Hamlets, and Southwark. Outer London includes boroughs like Croydon, Ealing, Barnet, and Bexley. The Fringe zone extends into areas just outside Greater London, including parts of Surrey, Essex, Hertfordshire, and Kent that fall within the designated high cost area boundary.
It is worth noting that HCAS does not change your AfC pay band or spine point — it simply sits alongside your salary as a separate supplement, and both elements are subject to income tax, National Insurance, and pension contributions.
Let's take a concrete example to see how NHS Inner London weighting changes your actual pay packet. A newly qualified Band 5 nurse or allied health professional starts at the entry point of £29,970 per year under the national AfC scale. Add the Inner London HCAS of £20,480 and your total gross salary becomes £50,450 per year, or approximately £4,204 per month before deductions.
Here is how that monthly gross breaks down into your actual take home pay. Band 5 Inner London sits just above the higher rate tax threshold of £50,270, meaning the vast majority of your earnings are taxed at the basic rate of 20%, with a very small slice above £50,270 taxed at 40%.