You normally shouldn't have to worry about the legal status of your courier, because there are many laws and regulations in place in order to ensure that any Miami courier service is going to be operating in a legal and aboveground manner. Most courier services have strict policies, for example, against hiring anyone with any prior traffic or theft related convictions in order to protect the security of their vehicles and their cargo.
Careful background checks are done on all drivers in order ensure that only responsible and safe people are going to be in control of your cargo. You can be sure that most companies maintain a policy like this because without one, word would quickly get around and they would have a very difficult time getting customers. Also, the insurance that a courier company must have on all of the vehicles in their fleet can also impact the legal status of their drivers, as their insurance can be void if the company is not adequately researching the safety of their drivers before putting them behind the wheel.
With any kind of company that deals in the kind of value that a courier company deals with, any lapse in their legality is something that is going to be immediately reported to the governing bodies, and such a company will not stay in business very long. If you have some reason to be suspicious about the legal status of a delivery company, you could always check with a transport official or with your local police force in order to discuss your concerns further. Generally speaking however, this is an industry where all the necessary legal safeguards are in place and effectively enforced.
There is another, more subtle indicator that can let you know about the legal status of a smaller courier company. Many small companies have working arrangements with larger companies like DHL and FedEx. These corporate giants however, are not going to partner themselves with any company that could place them in any sort of legally liable situation. Those companies also have gigantic legal departments working for them, while you likely do not, so you can trust that if they are willing to do business with a courier company that they have been thoroughly investigated and have been found to measure up to all legal standards, and you should feel perfectly safe about using them for your delivery requirements.