I wonder if any of your wonderful people can help me out of a hole?

My client claimed Incap in March of last year and originally claimed from 26 December 2005 via the telephone to Jobcentre Plus, but when his doctor provided him with a med cert from 16th January 2006, he amended the paperwork to claim from the 16th January 2006 before submitting it to the Jobcentre Plus.

He was awarded credits only because of insufficient NI Credits, he subsequently provided a further sick note backdated to November 2005 but this was in May so he was then beyond the 3 months backdating.

I am now (clutching at straws) looking for what constitutes an amendment of claim? my client put a line through the dates and written the new date and signed each amendment, but he didn't date the amendment. Any caselaw on this?????

Thanks in advance