A fax service is a business that sends and receives faxes for other people, typically for a small charge or as a part of a larger service. Many businesses that have a lot of walk-in clients, such as private post offices, wrapping and shipping services, copy centers, and real estate offices often also offer fax service as a way of supplementing their income while providing customers with another reason to come into the office. Such services can also be found through various online providers.