Private investigators are sometimes hired to locate and/or identify the physical address of someone who owns a Post Office box (PO box) or Postal Mail box (PMB). In the field of private investigations, it is referred to as a "Post Office Box break" or "reverse Post office box," and can often be accomplished if you are able to access some form of database that makes use of credit headers. This is due to the fact that most people who have PO boxes usually use the address to pay credit card bills, car payments, and so forth; thus, the PO box will appear on their headers as an alternate address. This information is updated frequently.
Should this strategy fail, there's a chance that you will be able to obtain the address via contacting the US Postal Service through a form available on the USPS website, and the form will also you disclose the reason you're looking for the information requested. They will release the information for legal purposes - for example, if a subpoena needs to be issued. In that instance, they will even require the court's case number, so it's important to be going into such a search for the right reasons and, more importantly, with the appropriate information on-hand!
So, sometimes these methods will nonetheless fail. What if the owner of the PO box has, in fact, relocated since opening the box? What if the owner of the box used a fake ID when opening the box? One method for discovering whether or not you've found the person you are looking for is to mail professional-looking statementl or even a phony love letter. And when the person resplies, you have successfully tricked him or her into giving up his or her real location. It may sound like a lot of work, and many investigators actually outsource much of this type of research for that reason. Mind you, it needs to be said that contacting the person directly can be risky and there is a chance that your investigation may be revealed. It should not be your first resort!
Nevertheless, an old sayings tend to ring true: There's no need to reinvent the wheel. So, many investigators will work together as a sort of loose-knit fraternity, selling and trading information back and forth as it is needed. And this applies to other sorts of location-based investigations, not simply a Post Office box break.
