List of Mumbai telecom companies
Landline Operators 
- MTNL: The largest and oldest operator in the telephone business in the central government owned Mahanagar Telecom Nigam Limited (MTNL). It has 2.5 million subscribers. Its subscriber base is high as it was a monopoly till the late 90's. MTNL phone numbers start with the prefix '2'.
- Tata Indicom (formerly Hughes Telecom): A new entrant, it has garnered about 200,000 subscribers. Tata Indicom is a relatively new player taking over Hughes Telecom in 2002. Its numbers start with '6'.
- Reliance Infocomm: Is the latest entrant in the landline space. Its numbers start with '3'.
- Airtel Broadband and Telephones: This is one of the latest ventures by the bharti group. Its numbers start with '4'. Although coverage is limited, but they are extending it to many parts of the city.
GSM Operators 
- Vodafone (404 020) : The 2nd largest GSM operator in Mumbai is Vodafone (formerly Hutch/Orange/MaxTouch). It has a large user base and has a large network (2G & 3G). Vodafone numbers: 9619,9769,9819,9820,9833,9920,9930,9169, 9167
- Reliance: (405 15) Reliance launched its GSM operations on 30 December 2008. Reliance Numbers: 9022,9699,8080. (2G & 3G)
- AirTel (404 092) : Airtel,(2G & 3G) started its operations in Mumbai in 2002-2003. Airtel has the advantage of being a national player. Airtel is owned by Bharti Group. Airtel Numbers: 9004,9165,9665,9867,9892,9967,9987.
- DOLPHIN (404 069) : Dolphin is the GSM branch of MTNL. The Postpaid mobile service brand is Dolphin while in Prepaid GSM service the Brand name is Trump. MTNL GSM service Dolphin along with Trump is operator of Mumbai which provide 2G and 3G both Mobile service. Dolphin Numbers: 9757,9869,9969.
- Loop Mobile (404 021): Loop Mobile (2G only) is a veteran in mobile telephony. However, it is not as large as Vodafone. Loop Mobile has been bought over by the Essar group and was to be integrated into Hutch by March 2006 but the deal failed. BPL has changed its brand name to Loop and with this new name claims to be the newest entrant to Mumbai circle.Loop Numbers: 9773,9821,9870,8082,966
- IDEA: (405 799) Idea is the GSM branch of Aditya Birla Group.Idea numbers: 9702,9594. 2G only in Mumbai.
- Aircel (405 805): Aircel (2G only) is the latest entrant to Mumbai circle. It has launched its operations in the month of April 2009. Aircel Number: 9768,8898.
- TATA DOCOMO (405 039): Tata Docomo (2G only) has launched its operations in the month of July 2009. Tata Docomo Number: 9029,8097. Virgin GSM is part of Tata Docomo Network (MVNO)
The specific number series for all operators are initially given by Government but since launch of Mobile Number Portability, a user can switch his service provider without changing his mobile number.
CDMA Operators 
CDMA operations make use of Wireless Local Loop (WLL). CDMA operations were launched in 2002.
- Reliance Infocomm: Reliance Infocomm is a CDMA operator in India. It has developed a good user base and is now competing to be the largest mobile operator in Mumbai. Operations started in 2003. Numbers start with '93' and are 10 digits long.
- Tata Indicom: Tata Indicom, like Reliance also offers CDMA connections. Tata now has operations on a national scale. Numbers start with '92' and are 10 digits long.
- Garuda: The pioneer in WLL technology, is run by the state owned MTNL. Operations started in 1999.
- Virgin Mobile using Tata network
- MTS new network
Tata Indicom and Reliance also offer Fixed Wireless Telephone Services. The phone connects to the base station on the network using wireless technology, instead of last mile copper wires. This cuts down on the need to dig up roads for laying out copper wires. This significantly reduces installation costs, speeds up the installation time and also reduces public inconvenience through less dug-up roads. It is also possible to connect to the Internet through Fixed Wireless Phones, either through captive broadband services or through dial-up connection to another ISP (Internet Service Provider).