Can you get selected from the Territorial Army to join the SAS?

Two of the three SAS Regt. battalions (21 & 23) are TA units. Basic Selection standards are similar to those for the Regular Army's 22 SAS, but the initial Selection process is spread out over about a year (every other week-end plus a two week period for final assessments), rather than the very intensive month that the Regulars go through. Some assert this makes TA Selection easier, but many disagree: it requires massive commitment to hold down a civilian job whilst maintaining the requisite fitness level, and spend 48 hours every other week running for many miles over rough country carrying a rifle and a massive load! Candidates must complete exactly the same tests/ marches (eg "Fan Dance"; "Sketch Map"; "Long Drag") to the same standard as the Regulars.

Continuation Training is likewise very similar to that of the Regulars, but does not include the "Jungle Phase". Again, it is spread out over a year or more, and includes weapons and tactics; Standard Operating Procedures; survival skills & SERE ("Combat Survival"); patrol skills (medical, signalling, demolitions, languages); advanced reconnaissance skills; unarmed combat & close quarter combat; parachuting etc.. Although some TA SAS Troopers train in advanced free-fall parachuting (HALO/ HAHO) and combat diving, the main emphasis of TA SAS training is on the "classic" SAS roles of long range reconnaissance, raiding, and guerilla warfare.

The Territorial SAS battalions function primarily as long range reconnaissance units, but may also conduct raids and other such tasks. They do not train in "Counter Revolutionary Warfare" and counter-terrorism, but are tasked with things like "combat rescue". A number of TA SAS troops are serving in Afghanistan, and probably elsewhere!

It is not unknown for members of the TA SAS to transfer to the Regular SAS (eg Chris Ryan), but in order to do this they have to formally enlist in the Regular Army (and undergo a nominal period of training - usually recruits' final field exercise/ assessments with a "parent" regiment, typically the Parachute Regt), and they also have to repeat Selection and Continuation Training, especially the Jungle Phase.