// Army officer · Army Officer (AOSB)
Army Officer Selection Board (AOSB) practice
The Army Officer Selection Board has two stages at Westbury in Wiltshire – a two-day Briefing and a residential Main Board. Here is what the British Army publishes about each one.
- Briefing, then Main Board
- Westbury, Wiltshire
What we know about the selection process
The British Army sets out the regular officer route in three stages: an interview with your local recruiter, the Army Officer Selection Board, and the steps after assessment (British Army – Officer application process).
Recruiter interview
The first stage is an interview with your local recruiter, held by online video call. The Army says it is a chance to get to know you, to see whether you would get on well in the Army and for you to ask questions. You are also given advice on getting ready for the Army Officer Selection Board.
AOSB Briefing
AOSB has two parts, Briefing and Main Board, both in Westbury, Wiltshire. You are sent to Briefing once your recruiter thinks you are ready. Over two days you are assessed on physical and practical exercises and taught how to prepare for Main Board (British Army – Officer application process).
The Army’s officer assessment page says Briefing is where you can start showing who you are, so you should arrive well rested and well prepared. It adds that the tests are designed to help the Army understand your development needs before Main Board. If your performance shows you are ready, you are put forward for a place (British Army – Officer assessment).
AOSB Main Board
Main Board is a residential assessment, and the Army says it lasts four days. You need to arrive physically and mentally fit because the tests are demanding, and you may be advised to wait between Briefing and Main Board so that you arrive ready to perform at your best. The Army says assessors are looking for your potential, not a finished product, and that every aspect is assessed – no single activity will lead to non-selection (British Army – Officer assessment).
The Army’s page sets out a day-by-day programme for the three-day Main Board (Short) used for Professionally Qualified Officers and specialists, who do not normally attend Briefing. It gives a good idea of the activities:
- Psychometric tests – a measure of your cognitive and personality profile, practised online beforehand through a link you are sent.
- Group discussion – with a short two-minute introduction from each candidate.
- Essay and lecturette – a short written essay and a five-minute talk.
- Interviews.
- Leaderless tasks and practical tasks – group problem solving outdoors.
- Planning exercise – described below.
- Multi-stage fitness test – the Army says candidates should aspire to reach level 8.7.
- Command task – outdoor activities where you take turns to lead the group.
The planning exercise
The Army calls the planning exercise a test of conceptual problem solving. You first work alone on a written assessment, then discuss it as a group. Your written submission has two elements: a short set of focused questions, including a copy of the scenario map to add information to, and an open answer sheet for your thinking. That covers four areas – aims, factors, options and your plan – and you are then asked to justify your plan (British Army – Officer assessment).
After AOSB
Once you have passed, you receive an offer of a place at Sandhurst, subject to background checks. You then attend a pre-commissioning course, which includes a medical, before starting the 44-week course at Sandhurst (British Army – Officer application process).
Sources
- British Army – Officer assessment: https://jobs.army.mod.uk/how-to-join/army-assessment/officer/ – accessed 23 October 2026 via an archived copy from August 2026
- British Army – Officer application process (regular officer): https://jobs.army.mod.uk/how-to-join/application-process/regular-officer/ – accessed 23 October 2026 via an archived copy from May 2026
- British Army – Does the AOSB for PQOs have a different pass rate to that of a regular soldier? (Q&A, December 2021): https://ask.jobs.army.mod.uk/discussions/does-the-aosb-for-pqos-have-a-different-pass-rate-to-that-of-a-regular-soldier-and-how-best-to-prepare – accessed 23 October 2026
Army Officer Selection Board: frequently asked questions
What is the planning exercise?
The Army describes it as a test of conceptual problem solving – a solo written assessment followed by a group discussion. Your written answer covers aims, factors, options and your plan, and you are then asked to justify the plan.
Can I fail AOSB because of one bad activity?
The Army says every aspect is assessed and no single activity will lead to non-selection. The assessment looks at your ability to develop through training at Sandhurst.
How long is the Main Board?
The Army's regular officer application page says the Main Board lasts 4 days. Professionally Qualified Officers normally attend a 3-day Main Board (Short) programme instead of Briefing and Main Board.
How should I prepare?
The Army advises researching which part of the Army you want to serve in, making sure you can easily meet the fitness standards, keeping up with current affairs, especially about society and defence, and being yourself.
What is the best preparation for Main Board?
A staff answer on the Army's Q&A site says to pay attention at Briefing, where you get the information you need and personalised feedback.
Source: British Army – Does the AOSB for PQOs have a different pass rate? (Q&A, 2021)
Related practice
- Applying to join as a soldier rather than an officer? Soldier selection uses a different aptitude test – practise it with our Army Cognitive Test practice.
- Considering officer roles in the Royal Navy or RAF as well? Their aptitude test differs from the Army's – see our Defence Aptitude Assessment practice.
Facts checked on 23 October 2026.