There are four distinct forms of taxicab, which can be identified by slightly differing terms in different countries:

Although types of vehicles and methods of regulation, hiring, dispatching, and negotiating payment differ significantly from country to country, many common characteristics exist. Disputes over whether ridesharing companies should be regulated as taxicabs resulted in some jurisdictions creating new regulations for these services.

Wheelchair accessible maxicab, unloading a wheelchair-using passenger in Australia

In recent years, some companies have been adding specially modified vehicles capable of transporting wheelchair-using passengers to their fleets. Such taxicabs are variously called accessible taxis, wheelchair- or wheelchair-accessible taxicabs, modified taxicabs, or "maxicabs".

Wheelchair taxicabs are part of the regular fleet in most cases, and so are not reserved exclusively for the use of wheelchair users. They are often used by non-disabled people who need to transport luggage, small items of furniture, animals, and other items. Because of this, and since only a small percentage of the average fleet is modified, wheelchair users must often wait for significantly longer periods when calling for a cab, and flagging a modified taxicab on the street is much more difficult.

Most taxi companies have some sort of livery on the vehicle, depending on the type of taxi (taxi, cab, private hire, chauffeur), country, region and operator.

Most places allow a taxi to be "hailed" or "flagged" on the side of the street as it is approaching. Another option is a taxi stand (sometimes also called a "cab stand," "hack stand," "taxi rank," or "cab rank"). Taxi stands are usually located at airports, railway stations, major retail areas (malls), hotels and other places where a large number of passengers are likely to be found. In some places—Japan, for example—taxi stands are arranged according to the size of the taxis, so that large- and small-capacity cabs line up separately. The taxi at the front of the line is due (barring unusual circumstances) for the next fare.

Passengers also commonly call a central dispatch office for taxis. In some jurisdictions, private hire vehicles can only be hired from the dispatch office, and must be assigned each fare by the office by radio or phone. Picking up passengers off the street in these areas can lead to suspension or revocation of the driver's taxi license, or even prosecution.

Other areas may have a mix of the two systems, where drivers may respond to radio calls and also pick up street fares.

In offices using radio dispatch, taxi locations are often tracked using magnetic pegs on a "board"—a metal sheet with an engraved map of taxi zones. In computerized dispatch, the status of taxis is tracked by the computer system.

Taxi frequencies are generally licensed in duplex pairs. One frequency is used for the dispatcher to talk to the cabs, and a second frequency is used to the cabs to talk back. This means that the drivers generally cannot talk to each other. Some cabs have a CB radio in addition to the company radio so they can speak to each other.

In the United States, there is a Taxicab Radio Service with pairs assigned for this purpose. A taxi company can also be licensed in the Business Radio Service. Business frequencies in the UHF range are also licensed in pairs to allow for repeaters, though taxi companies usually use the pair for duplex communications.

Taxi dispatch is evolving in connection to the telecom sector with the advent of smart-phones. In some countries such as Australia, Canada, Germany, the UK and USA, smartphone applications are emerging that connect taxi drivers directly with passengers for the purpose of dispatching taxi jobs, launching new battles for the marketing of such apps over the potential mass of Taxi users.

Taxi fares are set by the state and city where they are permitted to operate. The fare includes the 'drop', a set amount that is tallied for getting into the taxi plus the 'per mile' rate as has been set by the city. The taxi meters track time as well as miles in an average taxi fare.

Different states have different regulations for taxi driver registration and compliance:

Drivers must comply with work-time rules and maintain a logbook, with the onus on training falling on companies and drivers since the P endorsement course was abandoned.

Taxi companies claim that deregulation would cause problems, raise prices and lower service level on certain hours or in certain places.

The results of taxi deregulation in specific cities has varied widely.