Just had a call from an 01587 code (several over the past few days) and apparently it is a well known scam number. I just let it go to answerphone and the caller hung up. If you do answer it, the caller will tell you to press certain buttons on the keypad, so this is just a heads up.
https://www.unknownphone.com/search.php?num=01587
https://www.unknownphone.com/search.php?num=01587