Working age HB Regulation 100/State Pension age HB Regulation 81 states that all overpayments are recoverable unless:

 

• the overpayment was caused by official error, and 
• the claimant (or someone acting on their behalf), or anyone to whom the HB was paid (e,g. a HA / private landlord), did not materially contribute to the error, and 
• the claimant (or someone acting on their behalf), or anyone to whom the HB was paid , could not reasonably have been expected to realise there was an overpayment.

 

Overpayments have different causes, which can impact on how they are appealed, and also on who can submit the appeal about recoverability - in the main this will be the claimant. But for HA and private landlords where the overpayment is deemed recoverable from them, they may wish to appeal recoverability too. 

 

And note that a duplicate payment when HB has continued after someone moves onto UC is a non-recoverable payment as far as the HB office is concerned, but will be taken into account as income for UC. More here.