When I bought my current home in 2007 I spent several years dealing with the previous owner's creditors.
As I was about to move in I contacted BT by phone to arrange for my number to be transferred as I wished to keep it and my new home was in the same exchange area. The BT operator asked me if I knew the current owners, was I related to them etc. All seemed a bit odd at the time, but they were probably already chasing debts to the address.
When I actually did move in I discovered prepayment meters in the meter cupboard which I thought was rather strange especially for an owner occupied house.
Within days a window envelope arrived the contents had slipped and I could see "Notice of Intended Action". I opened it and discovered it was from either BT / Sky or Virgin. Can't recall which now but I ended up having to deal with all three comms companies over the next few years and their debt collectors. Then there were the banks, utilities, credit cards and various other organisations.
The previous owners had not left a forwarding address or arranged for Royal Mail forwarding.
Thus all their mail was coming through.
All I had was their solicitor's address who had undertaken the conveyancing.
The only way to stop it was open all the mail and contact the various companies, quite often by phone as I wanted some instant feedback from a human and I gave the companies the solicitor's address as point of contact.
I was also a bit concerned should my address be black listed as a credit risk should I wish to obtain future credit. I don't tend to buy much on credit but I like a new car now and again.
The previous owners were a couple who when then moved in were not married only marrying later.
They had children and the wife started using a mix of her maiden and family name to obtain credit.
The eldest son was also getting to the age of being to obtain credit and was also also trying on the same name trick. After they moved out they were still using the address to obtain credit.
It took about 9 years to stop the debt related mail coming through.
The very last one was about 2016. It was a hand delivered bill pushed through the letter box for £6,000 from a plant hire business for the hire of a concrete crusher!
I subsequently found out from a near neighbour that the couple had separated and the woman had gone to live with a builder - she was using her maiden name again still using my house address to hire the crusher.
Since then nothing.
Personally I would open mail that comes through.
Anything with your address on is your business.
if I had just put all this correspondence back in the post box it could have continued longer, bailiffs could have turned up etc.
Plus I think companies and organisations need to be informed that something is going on.