Tracing License Tag Numbers. If you have ever wanted to lookup somebody on the Web utilising simply a license plate number, you probably realize by now that this is no simple job. Even though there is great call for for a free up-to-date license tag lookup database, no such function actually exists. If you must acquire the proprietor of a car using a license plate number, you will require to either get the service of a law enforcement officer, employ a private detective or acquire the help of an online detective service which provides license plate search services. Beyond these options, you will not have any different way to hunt license plate data points on your own.