go back to country of origin

hi i am an ilegal immigraint(immigrtion abscondar) i want to return to my country of origin for entry clearance. I havent got pasport
how do i go about that
Do i have to tell the HO or not?
any advice please
thanks

First, you would need to apply for a passport from your country's Embassy. If that is impossible, then you would need to apply for a travel document from the Home Office.

You could approach http://www.iomlondon.org/ for advice on voluntary return. Not sure how this would affect a future application to come back to the UK. Perhaps you could post more details about your situation, like where are you from, what visa did you come on, what kind of entry clearance you are hoping for......