Accountancy encompasses a very wide net in the world of business, so before taking a leap, it would be good for you to have an idea about where you want your career trajectory to go. There have been various comments about AAT, CIMA, ACCA and ACA, each path tends to signpost a specific career path.
AAT - pretty basic, you will be working on entry level accounts assisting. I think this is a pretty boring place to be.
CIMA - professional exams, tends to focus more on in-house (ie working as a management accountant). You need to have a business sponsor who will sign off your skills over your qualifying years, and you will need to sit a lot of pretty tricky exams.
ACCA - as above, but with a more technical angle, often taken by people working in accountancy firms.
ACA - working for an accountancy firm, as above. I'm ACA qualified, so I may be well off the mark for CIMA and ACCA, but my grounding was about law, economics, marketing, customer service, business partnering, report writing, preparing accounts and tax returns, understanding all aspects of technical accounting and tax while working for a large accountancy firm (I trained in audit). Many, many qualified ACAers go into business management, lots of FTSE100 CEOs are actually Chartered Accountants.
I will say the exams were the hardest thing I've ever done, and we were told that our first year exams (the 'easy' ones) was the equivalent of taking 6 A Levels in 3 months, so not for the faint hearted, and not to be entered into lightly (my firm sacked those who failed a first year exam as it was an indicator that the pace wouldn't be right for them).
Personally, I think it has been an excellent career (I qualified 25 years ago), I've worked in the Big 4, a small accountancy firm, and across many different in house roles. Once I had children, I was easily able to work PT, and now my children are grown up, I've scaled back up to work FT. Deadlines are time-pressured, but I've put lots of systems in place to make them go as smoothly as possible. Go into it having researched, and find the right path for you.