This is an old post. Note that the AA periodically updates its franchise options, and there several variations available.
EDIT: 19/8/2019: This has started to get a few hits recently. It seems the AA has changed its franchise options. I will update this very old article when I get more information.
Just to keep the balance with the previous post about another school, you can read up on this on the AA’s website.
The AA’s full franchise costs about £230 a week, and this falls by about £5 a year as a loyalty bonus up to 10 years (edit (2022): there is no longer a loyalty bonus). Franchisees pay between £20-40 for each pupil who the AA passes on to them, although this is waived or reduced for certain pupils (e.g. those who are only doing Pass Plus, or for new pupils who have a test booked imminently and whom the instructor agrees to take on).
There are two franchise-free weeks every year around the end of December, though apparently (since 2015) you can now take these anytime you want.
The AA also has a car-only option (no AA livery and no access to pupils), which costs about £120 a week.
Vehicle are now (since 2015) replaced annually and there is a mileage cap.
From what I now understand, Ford Fiestas are the preferred vehicle although the Focus is still available for an additional weekly fee on top of the standard franchise.
The AA used to have a reputation for being the best value franchise option available, but the prices are beginning to look quite high these days. One instructor told me that increases in the franchise fee outstrip the loyalty bonus (edit (2022): there is no loyalty bonus anymore), so even long serving instructors gradually pay more year on year. I’m also told that vehicle specifications regularly change without warning – someone somewhere is probably saving money, but not the ADI. Remember this is what I’ve heard and cannot vouch for it.