It is completely legal to track your own lost device, so you don’t need to worry about privacy laws in this situation. Those regulations are designed to prevent spying on other people without their explicit consent. Since you own the phone and are actively trying to recover it, using an online tracker is perfectly fine. You can check out this website to pinpoint its current location using just the phone number. The tool works by sending a tracking message to the device, and once it’s opened, the GPS coordinates will show up on a map. Just try to do it quickly before the battery dies or someone turns it off!