What do the SAS reserves actually do?
By Deepak Shukla · Historical account and source-led commentary
The SAS reserves — 21 SAS and 23 SAS — are part of United Kingdom Special Forces, staffed by people who hold civilian jobs and train around them. Reserve service means regular training commitments in your own time, with the possibility of deploying in support of operations.
Service around a job
The honest description of reserve service is that it consumes the time other people spend resting. Weeknights, weekends, annual leave. Nobody supervises the training you do between commitments, which means the whole thing rests on whether you will run in the dark and rain when nobody would know if you didn't.
Do the reserves deploy?
Reserve special forces personnel have deployed on operations, but what any individual does, where and when is not something the Army publishes and not something I have first-hand knowledge of. Anyone claiming to give you specifics online should be treated with suspicion. Ask the unit.
Are the reserves respected?
It is the question people actually type into Google, so here is the honest answer from the outside: the selection process makes no allowances for the fact that you have a job, and the people who get through it are, without exception, the ones who took the preparation seriously for months. Whatever anyone thinks of the badge, the standard required to reach it is not a soft one.
A note on accuracy
Entry criteria, standards and selection dates are set by the Army and change over time. Take anything current from the Army's own UK Special Forces Reserve pages; take everything below as one applicant's experience.
What is current policy, and what is my own experience?
I applied to 21 SAS and completed preparatory British Army training in 2015–2016, but did not attempt SAS selection or serve as an SAS operator. My private Georgian training was a separate experience. Military requirements belong to the Army, not to this independent personal website.
Published sources
- British Army Jobs — SAS Reserve role, entry requirements, selection and locations
Primary source for the role and the five publicly described phases; checked 15 October 2026.
- British Army — UK Special Forces Reserve overview and recruiting contact
Official route to the latest unit advice; checked 15 October 2026.
- British Army — 21 and 23 Special Air Service Reserve
Official regiment information; use the Army for current recruitment, not my historical diary.
- Soldier magazine (October 2025) — SAS Reserve recruiting feature
Dated official magazine article. Some eligibility wording differs from the Army Jobs role page; confirm with recruiting.
The Army Jobs listing and the October 2025 Soldier article use different age wording. That is a reason to ask the recruiting unit, not to pick the most convenient figure. These references are checked as of the date above, not monitored automatically.
Get my 21 SAS reserve selection prep guide
What the stages are, what I was training to before I applied, and how I'd build the twelve weeks before a selection weekend. Written from my own application, free, no pitch.