Bates & Others v Post Office Ltd

Bates & Others v Post Office Ltd was a UK group legal action taken by 555 subpostmasters against Post Office Limited, commonly known as the Post Office, the state-owned post office company. It was heard by Justice Fraser in the High Court between 2017 and 2019. Six judgments were handed down, two of them dealing with substantive matters while the rest dealt with procedural matters. The Common Issues trial examined the contract between the subpostmasters and the Post Office and found largely in favour of the claimants, while the Horizon Issues trial found that Horizon, the Post Office's accounting software, contained bugs, errors and defects that could cause shortfalls in the subpostmasters' accounts.

Further scheduled trials were not held, as the claimants and the Post Office settled after the Horizon Issues trial. The action was part of the response to longstanding injustices which later became known as the Post Office scandal.