The Florida Department of Highway Safety and Motor Vehicles (HSMV) gives information on that one should do if they were at fault in an accident and were without insurance.
If there was bodily injury and property damage to eliminate the possibility of suspension, your son should purchase a full liability insurance policy (which means that it includes bodily injury liability as well as PIP and property damage liability) as soon as possible and advise the company that he was involved in an uninsured crash and may need a Form SR-22 (certification of liability insurance) in the future.
He will also need to negotiate with each person or their insurance company to satisfy the losses they incurred. If he is unable to pay the damages in full, he can try to negotiate a payment agreement to allow monthly payments.
The HSMV notes that one should always have a document completed to legitimize the agreement to be used as proof of payments required by this state department. Release forms can be obtained from a Florida driver license office.
If person that he rear-ended used their insurance company and their insurer has compensated them for damages then your son should contact the insurance company for satisfaction of damages since the insurance company has assumed the loss and will likely subrogate with him so that he will be required to repay them.
If no one received bodily injuries in the accident then your son's accident will not fall under the FL Financial Responsibility Law but is subject to the Florida Motor Vehicle No-Fault Law. The law requires that an owner whose vehicle is involved in a crash and the operator was charged with a moving traffic violation, must have in effect a policy with limits of $10,000 personal injury protection per person/per crash and $10,000 property damage liability per crash (compulsory coverage).
The Florida Financial Responsibility Law is the one referred to earlier where the driver/owner must also obtain bodily injury liability coverage.
Your son will still need to negotiate with either the other party or their insurer even if the accident only had property damage and not bodily injury. With the insurance coverage and releases or monthly repayment agreements, your son will be able to provide them to HSMV to avoid unnecessary suspensions of his driver license, tags, and registrations.
If your son was cited for driving without insurance then the penalties associated with this offense include suspension of your driving privilege, vehicle tag and registration, for up to three years or until proof of Florida insurance is provided, whichever is first. If your driving privilege is suspended because you are not properly insured, there is also a penalty to reinstate your license. A reinstatement fee of $150 up to $500, for subsequent violations, must be paid and you must provide proof of current Florida insurance.
For your son to get the required insurance, including the SR-22, he can come to us for a car insurance quote.