Dozens of former sub-postmasters and postmistresses should get a clear path in quashing their convictions for fraud, theft and false accounting.
They were convicted of stealing money after the Post Office installed a new computer system, with some imprisoned.
Many have now been told the Post Office will not contest their appeals against conviction.
For years, their criminal record put some of those affected in dire financial circumstances.
Some struggled to secure work, lost their homes, and even failed to get insurance owing to their convictions, but always said the fault was in the computer system.
The decision paves the way for more than 30 cases to being quashed, although the Post Office can seek a retrial. More cases remain under scrutiny.