The consumer watchdog has accused payday loan companies of "irresponsible lending", "pressure tactics" and other bad practices.
The OFT has given them them 12 weeks to prove they provide an important service, or else they could face closure.
However, there will be no cap on interest rates.
Consumer Editor Chris Choi reports:
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Mr Kim has made two recent visits to China.
The study looked at the development of 422 children over the course of eight years.
The president said they will come into force if China refuses to change its practices.