HP Serial Number.
Before anyone loses his/her mobile phone, one should first check the serial number of the phone by keying in *#06# where a 15-digit number will appear
on the screen. Please record it down and keep it for reference.
In case the phone is lost, the rightful owner can call the service provider to disable the phone by providing the serial number.
That means, the person who took the phone cannot use it at all even if they
insert a new SIM card. If everyone knows this procedure, there would not be much use taking away someone's phone. Please feel free to circulate this