Pupils who appeal against their grades should have their case heard by a three-person panel and a friend or parent should be allowed to speak on their behalf, guidance to schools says.
Teachers' leaders attacked the move as "bureaucracy gone mad" and said there was no evidence of a problem in teachers' marking of coursework.
Exam boards are required to issue guidance under rules set out by the Qualifications and Curriculum Authority in England and UCAC in Wales but this is the first time they have produced detailed rules.
The guidance sets out 13 "minimum requirements". In addition to the tribunal these include:
* access for all candidates to a copy of the appeals procedures; * a written record of appeals which should be shared with exam boards on request; * access for all candidates to marks, moderation and correspondence concerning their work.
The guidance covers vocational GCSEs and GNVQs (dubbed vocational A-levels) as well as their academic counterparts.