A friend whom used to live at my address recently had a letter in post from Scotcall, but was sent to my address as was last known here. It was regarding an alleged specified amount owed to a mobile phone company about 3 years ago. I guess my friend should send the 'prove it' letter, but do you think my friend should include their new address on the letter? Probably a stupid question! Also I presume this will not affect my credit record?