Hey! What branch are you interested in? If you are seriously considering it, get yourself in a soon as, time is of the essence when it comes to the armed forces, and alot is based around your age. The first time you walk into an AFCO, they will ask you what you are interested in job-wise in their service and what sort of grades you have to see if you are eligable for whatever job you are looking at... You wont be judged on your initial meeting because its mainly for you to ask questions about them and get as much information as possible, don't worry you are not expected to be an expert in any sense. Obviously know what the RAF is about (protecting britains intrests, humanitarian aid etc.) but thats about it at this stage. If and when you apply is when you have to start genning up on knowledge about the service!