Notification of an ‘intention to claim’ IS

Does anyone know of any case law that might define what would qualify as a ‘notification of an intention to claim’ IS.

Following a change of circs client sent in an IS10 but heard nothing. He wasn’t on IS at the time, just IB,  but it wasn’t until his social worker followed it up some five months later did the DWP write to him to say that he actually needed to claim IS.

My contention is that an IS10 recieved from someone who doesn’t get IS capable of being construed as an ‘intention to claim’ IS as it has no purpose other than to increase an award of IS. In that case Reg 4(5) of the claims and payments comes into effect and the claimant should have been given an A1 form as soon as the IS 10 was looked at.

It would be preferable for the IS to be backdated to the date that the ‘intention to claim’ was made as this would simultaneously generate a backpayment of HB and C Tax Support.

Failing that I think it would have to be a claim for maladministration in that DWP conspicuously failed to respond in a reasonable manner to a form they had recieved- it isn’t rocket science to write back to someone who has sent in an IS10 and tell them they should claim IS.

Any thoughts or case law gratefully recieved