My client was told she could be entitled to extra benefit following a home visit on Friday, later in the day she received a call to notify her that it was in fact her who owed money.

When she queried the amount of tax credits they had based their decision on they realised that they had the wrong paperwork and that it had been mixed up when photocopying. They want her to pay back the amount from May 2006 stating that she should have realised the mistake when she received her entitlment paperwork.

I have advised her to appeal.
Any advise on how best to approach this?

Many Thanks

The issue is one of recoverability due to official error which claimant ought reasonably to have been aware at the time of receiving payments or notifications.

The issues which tend to get considered are the clarity (or otherwise) of the notifications; claimant's likely knowledge of the benefits system (inferred from how many claims person has made or many times entitlement has been assessed); the scale of the error (is it a big one-off mistake or a comparitively small weekly discrepancy which has just mounted up over a period of time). You don't say when and in what form she queried the tax credits taken into account; what led her to query it? Maybe the LA is basing their decision that she knew HB was wrong on the fact that she queried it? But it would probably depend on the precise circumstances as to whether that is a reasonable assumption on their part.