PHP / Mysql Script function

Hello I am building an application like whatsApp. The flow of the application I have built is as follows. The user starts the application on their iPhone, They insert their mobile number in Country format ie +4475665... , I then save that number in a database table on the server. I then grab all the phone numbers from the users phone and compare the list of numbers in that list to the saved numbers on the server and return the matching numbers. I am looiking for someone to build the compare script in php for me, so it is clever to look for numbers with +44 ect country code vs someone not puttin count number in ie 787987. I have started the script but need some help. This should be very easy job for mysql expert. Thank you