Tahir Mahmood, who kept Selly Oak Post Office, was jailed for nine months in 2005 for false accounting.
But, along with seven other former post office workers, he was on Wednesday granted the right to appeal his conviction.
The decision by the Criminal Cases Review Commission means that a total of 47 convictions based on evidence from the Post Office's controversial Horizon computer system have now been referred to the Court of Appeal
They claim a glitch with the system created financial discrepancies which led to charges of theft or false accounting.
Also among the 47 former Post Office workers fighting to clear their names are Tracy Felstead, from Telford, jailed for six months in 2001, and Rubbina Shaheen, who kept Greenfields Post Office in Shrewsbury, jailed for 12 months in 2010.
Former West Bromwich postmistress Neelam Hussain, jailed for 21 months in 2011, has also been granted an appeal.
Last year the Post Office agreed to pay out £57.75 million to 555 ex post-office staff who claimed they had been falsely blamed for financial discrepancies caused by the Horizon system.
The settlement came after a High Court hearing which led to Mr Justice Fraser concluding that that the Horizon system could have led to people being wrongly accused.