Until now, the four-year rule has not been enforced properly because no one has known who is responsible for monitoring it, and many teachers from overseas have continued to work here unchallenged.
However, the General Teaching Council is now clamping down. Gill Williams, The TES expert on graduate training programmes, said there were many different routes by which overseas teachers could acquire qualified teacher status, but they were often given inaccurate information.
"The procedure is quite complex," she said, "and involves teachers preparing portfolios, having their teaching assessed and producing documents from their countries of origin showing they are eligible to teach.
"We have set up a hotline* to give these teachers the advice they need, which is accurate and reliable and will point them to the best route to get QTS."
Details of problems with QTS emerged just two weeks after it was revealed that stricter visa controls are to be imposed on staff wanting to come here from non-European Union countries.
In future, visas will be offered for just one year, instead of two, with opportunities for teachers to extend them.
However, recruitment agencies have warned that any reduction in the amount of time teachers can work here will deter many from coming.
The Home Office has also announced that applications for extending stays in the UK will now cost pound;500, instead of the previous pound;121.
In 2003, the Home Office granted 5,281 working visas to teachers from Commonwealth countries, including 1,538 South Africans, 1,318 from Australia and 667 from New Zealand.
*You can speak to professional advisers on: 01223 463824