There’s not really an industry standard, it’s not a regulated industry and things are a bit complicated….
The ABTC is described as being the regulatory body, but to the best of my knowledge, it’s self regulated (and so there’s nothing to stop anyone setting up as a trainer or calling themselves a behaviourist).
Associated with the ABTC is the APBC. APBC members (behaviourists) are the ones recognised by the insurance firms, there’s a link on the APBC site to accredited courses which can lead to membership, e.g. you could do a Foundation Degree through Bishop Burton, and follow that up with the full time honours year.
Before you get that far, you might want to consider courses provided by other providers.
The IMDT courses are said to be good, though not cheap (haven’t done any myself).
I did a course with one provider I wasn’t particularly impressed with, and did another course through Canine Principles that I would recommend (Canine Coaching Diploma).
I’d suggest reading up on modern training methods, Classical and Operant Conditioning and the evolution of the dog to start with. A couple of good books (that you’ll end up referencing if you do sign up for a course)…
Excelerated Learning by Pamela J Reid (if you only buy one book, make it this one).
Culture Clash by Jean Donaldson – Excerpt Here.
In Defence of Dogs by John Bradshaw
Dogs: A New Understanding… by Ray Coppinger
Dominance in Dogs by Barry Eaton
Reaching the Animal Mind by Karen Pryor
That should do you to start!