Its legal victory sets back the pension transfer review, ordered in November by the Securities and Investments Board, the City's leading watchdog, by up to three months.
The IBRC, the insurance brokers' regulator, will have to wait for the outcome of a judicial review, for which leave to apply was also granted yesterday to the IFAA by the High Court.
Legal action to stop the IBRC was taken by the IFAA and a professional indemnity insurer, LIBM.
IFAs, which advised on up to a third of pension transfer cases, are opposed to the review because they face compensation claims of hundreds of millions of pounds from their clients. Indemnity insurers are worried that they would be the ones having to paythe mountain of claims.
Garry Heath, chief executive of the IFAA, said: "We are delighted to have obtained leave to apply for a judicial review in a matter of such importance to independent advisers.
"We have every confidence in the strength of our case. The issue has very serious implications for the survival of small businesses and the financial services industry as a whole."
A spokeswoman for the SIB said: "SIB believes its guidance was well founded and we are glad that the LIB challenge will be heard as as soon as possible."
The restraining order against the IBRC is expected to prevent other regulators from implementing SIB-inspired guidelines on the same issue. The Personal Investment Authority, the advisers' frontline watchdog, had planned to introduce them in the next twoweeks.