Those ESA 3 enquiry forms.

Just received mine enquiring as to wether I wish to back claim Income related ESA. I know that due to slowly selling off my old business assets down the years and I wouldn't be eligible. So apart from saying on the form that I know I wouldn't be eligible and don't wish to pursue a claim, do I return the full enquiry form in the return post un filled in, or just that last page which has the tick boxes on? Call me tight, but sending the whole thing back to them via registered post would cost a lot compared to just a single page.

Also what with Christmas being in the way I'm not sure the form will get to them in time for as per usual with them I received the form late in the day, so how flexible are they with the deadline? I imagine at most It will only be a week late?

Thanks.

I just leave the rest of the form blank though as I'm not pursuing a claim?