That's another story......
The previous owner bought the flat from newly built and rented it out. When there is no tenant in residence (between tenants and empty while the selling process went at a snail's pace during Covid lockdown) the owner of the property is supposed to pay the utility bills. If the tenant vacates leaving unpaid bills, the owner has to pay them then chase the tenant through the courts to get his money back. In the case of gas and electric, even though there is no-one there using anything there is still a daily standing charge payable.
When we finally got the keys to the flat in June 2021, the letterbox was stuffed full. The contents included estimated gas/electric bills for December 20, January, February, April and June 2021. There was no bill for March or May - we now know what happened to March's bill, but why no May?
Our son read both meters and contacted the company to say he'd just moved in so he was given a new account number. A few days later a final bill for old account arrived. We took all these bills to the estate agent who sold the flat and asked them to pass them on to the previous owner.
A few months later, three letters arrived at the flat from a debt collection agency, each for a different gas/electric account with unpaid outstanding bills. My husband composed a letter detailing the date we had bought the flat and giving the seller's name address from the conveyancing documents. He laid it on thick saying our son now lived in fear of bailiffs coming and removing all his property. It took a few months more but we finally had letters saying the bills were not our responsibility and they had made contact with the previous owner from the details we gave them.
The water bill was another issue.
Again our son contacted them to say he'd just moved in. In July the water company announced that every day that month if a customer submitted a meter reading, they would be entered into a prize draw, so our son read the meter every day and submitted the reading. Then he realised that his readings were going up and up even though he wasn't actually living there, he was living with us while he totally redecorated the flat. So he contacted the water company who sent an engineer out.
Our son had realised the problem straight away but the water company needed to confirm it. There are 6 flats in the building and 6 water meters outside. The bill gives the meter number, so our son looked for the meter with the number on his bill and turned the stop tap off. His water still ran. The engineer confirmed that the wrong meter had been allocated to his account. So not only did they write off the amount owing up to that date, they also credited his account with £40 for the inconvenience.