Why would they not be on the electoral role? it is a legal requirement to fill out the form, and to pay council tax if you are an adult. Even if you are exempt you will still be on the elctoral role.
to me it would mean someone is trying to hide, and therefore you are unlikely to find them on a website
thanks bednobs totally agree the person im trying to tack remarried leaving lots lots debt can not find iv searched 192.com and many more just cant find the ******.