21 SAS vs 23 SAS vs 22 SAS
By Deepak Shukla · Historical account and source-led commentary
22 SAS is the regular, full-time SAS regiment. 21 SAS and 23 SAS are reserve regiments whose members keep civilian careers and train alongside them. All three form part of United Kingdom Special Forces; the practical difference for anyone applying is full-time service versus reserve service.
22 SAS
The regular regiment, based in Herefordshire. Soldiers serving in 22 SAS do it as their full-time job, and the usual route in is from an existing career in the regular Army rather than from civilian life.
21 SAS and 23 SAS
21 SAS and 23 SAS are Reserve regiments. The British Army lists broad recruiting regions for each and describes a reserve service pathway with training alongside civilian life. Geography is one important practical factor, but it does not by itself determine eligibility or tell you which current opportunity is available. Use the official recruiting route for that advice.
What is the same
The Army describes demanding training and service requirements for the Reserves. My own experience was limited to application and preparatory Army courses; I did not attempt either Regiment's SAS selection and cannot compare their assessments from direct experience. I can speak to the real challenge of balancing a civilian life with Army training.
Which should you apply to?
If you are exploring full-time military service, begin with the Army's current regular careers guidance. For the Reserves, check the official SAS Reserve role listing and ask recruiters which unit and pathway suit your circumstances. Do not assume that reserve service is a shortcut into a regular Special Forces role.
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.
Read next
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.