Yes, a customer can add multiple vehicles to their New Hampshire E-ZPass account. When managing an E-ZPass account, individuals have the ability to link more than one vehicle by providing the necessary information for each vehicle, such as the make, model, license plate number, and any other required details. This flexibility allows for convenience, especially for families or individuals who use multiple vehicles frequently in toll areas. It is important for the customer to ensure that all vehicles are registered correctly to avoid any issues while traveling on toll roads. For specific steps on how to add vehicles or to find more information, it is advisable to refer to the current web page associated with New Hampshire E-ZPass.