I live in a block of flats. Can somebody who also lives in my flats, and who is not related to me, be my witness? - UK Deed Poll Office

I live in a block of flats. Can somebody who also lives in my flats, and who is not related to me, be my witness?

No, this may invalidate your Deed Poll and when you notify organisations of your change of name, they may not accept your Deed Poll.  If you have not yet executed your Deed Poll, we advise that you find someone else to be your witness.  If you have any duplicate copies that have not yet been executed, you should ask a different person to be your witness, destroy any Deed Polls that have been witnessed by your neighbour, and use the duplicate copies as your originals.