Although a licence was granted, the project was never realized due to the prevailing economic depression in the city brought on by the end of the American Civil War, during which Bombay had made vast strides in its economy by supplying cotton and textiles to the world market.

[1] On 9 May 1874, the first horse-drawn tram made its debut, plying the Colaba–Pydhone route via Crawford Market, and Bori Bunder to Pydhonie via Kalbadevi.

[4] The passing years aggravated the problem of rush-hour traffic, and to ease the situation, double-decker trams were introduced in September 1920.

Despite stiff opposition and protests by taxi drivers, the service ran without a hitch, transporting 600,000 passengers by the end of that year.

In response to pleas by the government and the Bombay Municipal Corporation, the company extended its services to the northern part of the city in 1934.

The Indian independence movement's call for mass nonviolent strikes and general civil disobedience led to regular service disruptions, causing the company to incur huge losses in 1929.

To remain solvent, it decided to introduce discounted fares for short routes and increase its coverage to the northern portions of the city.

By mutual agreement, the corporation also took over the operation of bus services, which were run by the Bombay Electric Supply & Transport Company.

The case dragged on for four years before the Supreme Court of India granted the organisation a complete monopoly over bus services in the Greater Bombay area.

In 1964, due to high operational costs and poor public support, its long-running tram services were terminated.

[9] With the renaming of the city from Bombay to Mumbai in 1995, the organization was rebranded as Brihanmumbai Electric Supply & Transport (BEST).

Following a Supreme Court directive, the company gradually phased out old buses and introduced new ones that complied with Euro III pollution control standards.

[10] On 19 November 2004, route SPL-8, travelling from Churchgate to the World Trade Centre, began accepting cashless smart cards for automatic fare collection on BEST buses.

[13][14] The company placed a ₹36,750,000,000 (US$420 million) order with Olectra Greentech to supply and maintain 2,100 battery electric single-decker buses for a 12-year period in May 2022.

Inside the buses, there are LED indicators displaying route and destination as well as upcoming stop names.

[19][20] BEST bus routes are spread citywide and extend to the neighbouring cities of Navi Mumbai, Thane, and Mira-Bhayandar.

[21] As of 2021, BEST ran approximately 3,800 buses,[22][23] ferrying 5 million passengers[24] over 443 routes, and had a workforce of 38,000, which included 22,000 drivers and conductors.

In August 2006, the company introduced payphone system and CCTVs on its buses as a response to terror attacks.