Claiming wrong benefit - UC instead of PC because of fault in passport

I don’t know if there’s any hope on this one. My client’s overseas passport had the wrong DOB and was out by several years. She claimed UC but should have been eligible for PC/HB. She has now claimed PC/HB, and has a large UC overpayment. At the time of the PC claim we wrote to UC and PC to ask if UC overpayment can be offset by PC backdating on the basis of ignorance of a fact. We’ve notified HB as well. Does anyone know if a request like this has been made before, and could it be successful?

What an extraordinary situation. How exactly did the wrong passport feed into it? E.g. did someone check her passport and advise her what to claim based on the DOB given in it?

I would think in circumstances like this, if she is being pursued for an overpayment but in fact has demonstrably been underpaid, you would have a strong case to request discretionary write-off and possibly look at a JR if refused.

I don’t know the full story of how it happened. But she didn’t know she’d claimed the wrong thing till she came to us with a refusal for SRP and we picked up the mismatch.
Thanks - that’s all helpful.