What is the minimum duty for a commissioned intelligence officer?

Hi, the minimum time to serve as an officer, regardless of Capbadge is 4 years (1 year at The Royal Military Academy Sandhurst and 3 years after). This is due to the time and cost training individuals. 4 years flies!

Thanks for your help, is there anything you recommend doing to get a taste for army life/ to know if it is something I would enjoy?

It depends on your age - CCF / ACF or if you are at university the University Officer Training Corps (UOTC). Once you have applied and gone through pre selection (The Army Officer Selection Board Briefing) you will have the opportunity to visit a Regiment / unit. Apart from that it's research and research and talk to people. You can apply, get all the way through (ie pass all the selection criteria) and then decide you don't want to do it. No-one is going to come and collect you and march you to the gates (so to speak). Ultimately a commission is 4 years service (of which one of the those years is in training) and I've never met anyone who left after only serving the minimum time who said they regretted it. You will learn things about yourself and put yourself through things you never would have thought possible and that can only be a good thing to bring to future employers and to know what you are able to achieve.