The Office of Fair Trading (OFT) has issued a statement explaining exactly what the Motor Industry Service and Repair Code will mean for consumers.
The code will require that when member garages provide a quote or estimate for work, they also put in writing a breakdown of costs including the charges for labour and parts.
It will stipulate that where it becomes apparent that further work is required, the member garage must first get the permission of the customer before carrying out this additional work.
Member garages which sign up to the code will not be able to take upfront deposits and these garages will be subject to inspection visits by independent RAC engineers who will monitor procedures.
Charles Wallace, OFT head of consumer codes, said: "Consumers need to know that when they take their car to a garage they are going to be treated in an honest and reliable manner.
"By using a garage that has an approved code, customers can be assured that they will receive a much higher standard of protection than required by law."