An Army Training Regiment (ATR) is a unit of the British Army which conducts basic training for all new recruits, less adult Infantry recruits who are trained at the ITC (Infantry Training Centre) at Catterick North Yorkshire, and some non-infantry TA units (see below). Junior (under 17.5 years) Infantry recruits are trained first in an ATR before going to the ITC to complete training as a combat infantryman.
All new recruits, whether Regular or Territorial Army, are required to pass the Common Military Syllabus (Recruits) (CMS(R)), commonly known as Phase 1. For regular, standard entry (17.5 years-33 years) recruits this is 14 weeks, for TA recruits this initial training is carried out over weekends at a Regional training centre followed by 2 weeks at an ATR. Not all TA recruits are trained at an ATR; for example, recruits for TA units of the Royal Military Police complete their CMS(R) at Worthy Down, near Winchester and recruits to UKSF(R) and the Honourable Artillery Company complete CMS(R) with their own units