I had a call the other day from an unknown number. Claimed to be from O2 regarding an upgrade being activated on my account. I know O2 only call from a couple of numbers so was confident it wasn't them so played along to see what info he had.

He read out my (correct) current address and asked if that was correct. I said no. He then read out my (correct) previous address and asked if that was correct. I said no. I then hung up and called O2 to confirm it wasn't them and make them aware if anyone tried anything with my account with them. Quite frightening that they knew, as a minimum, my phone number, current address and previous address.

I've set up a few extra alerts on my accounts and have been checking my credit file to make sure nothing untoward appears there.