Estate Agent- illegal?

[concertplayer]

Our house has been sold but not near exchange yet. The EA texted to say the
buyer had to leave his rented place and was going to relatives. He asked if
the buyer could redirect his mail to us and he the EA would pick it up.
We declined. 3 days later and onwards mail arrived but it was not redirected
He had moved water/sewerage bills to his name so using our address.
He even had driving licence at our address.

He's paying your water bills for you? Generous fellow.

This sounds very illegal.
The house sale could yet fall through for any number of reasons.
Have you contacted the EA?

Send back with "not known at this address" on envelope.

You need to contact the company name on the outside of the envelope and make sure that they know that the bills should still be in your name. Then return everything to sender. He could be using any of these things as proof of address to take out loans.

^ this

A few letters addressed to us ended up being sent to our new house before we'd moved in. That was no fault of our own though...the life insurance people sent them there even though they knew we hadn't moved in yet and we weren't aware until the day we moved in. So it might be nothing...

But the fact it's bills, driving licence and you haven't exchanged yet sounds dodgy. I wouldn't give them to the EA if I were you. Return to sender.