General Teaching Council quality checks intended to root out cowboy providers. England's general Teaching Council is to accredit teachers' workplace learning, to ensure schools are not spending their budgets on fly-by-night operators.
The GTC ultimately wants to see all workplace trainers partnered to its accreditation scheme, the Teacher Learning Academy. Numerous small companies have been set up in the past few months to sell professional training services to schools.
"I'm tempted to say that this is the last chance saloon for the cowboys," said Sarah Stephens, GTC policy director.
The proliferation of new training providers has been driven by changes to performance management regulations that came into effect last month, requiring professional development. Teachers' pay is now pegged to their professional development training.
Michael Mills, a Birmingham teacher, set up a new training company this year. But with no recognised industry quality mark, he said TLA partnership could be useful.
"I think there's a lot of jack-of- all-trades companies out there with hundreds of courses, and some of those courses are, frankly, boring," he said.
Nigel Middleton, a leadership trainer for 10 years, said that there had been a massive proliferation of providers this year - but many would be gone again within the next year.
"Your average primary school is receiving 100 flyers a week from these new providers, and most go straight in the bin," he said.
Keith Bartley, GTC chief executive, said that TLA partner providers would be subjected to quality checks.
"There are so many training courses that don't necessarily result in changed practice in the classroom," he said
The TLA asks teachers to design self-development projects, including any necessary training, research and mentoring, then to show how they have improved their teaching. It has been piloted in Manchester, Birmingham and Sheffield and will be launched nationwide in January.
During the pilot, one headteacher completed projects with several of her staff which she credited with getting the school out of special measures. A religious education teacher at another school did a project on using oral questioning to improve her lessons on the Koran.
Neil Dixon, 29, from South Bromsgrove Community High School in Worcestershire, is the first teacher to complete the top level of the TLA accreditation.
"In the old days, professional development meant going on an Inset day to a course at a nice hotel, and having a good lunch," Mr Dixon said. "But just doing what you did last year isn't good enough."
Like university thesis supervisors, trained TLA "verifiers" at schools around England will assess whether work makes the grade.
The GTC, which has spent pound;2 million a year to develop the TLA, wants to have 10,000 teachers complete a stage by 2009.