The acronym "GSP" stands for Gradsko saobraćajno preduzeće (Serbian Cyrillic: Градско саобраћајно предузеће, lit.

[citation needed] Its history dates back to 14 October 1892 when the first horse tram line began operating in Belgrade between Slavija and Terazije.

It was known under the name Beogradska varoška železnica (Serbian Cyrillic: Београдска варошка железница, lit.

During 1994 and 1995, the GSP managed to raise the level of transportation, revitalize the fleet to an average of 909 vehicles on weekdays.

After the start of NATO bombing of Yugoslavia on 24 March 1999, GSP "Beograd" transferred to work in the war environment, which meant the abolition or curtailment of a large number of lines.

The outdated fleet, low technical condition of vehicles, lack of spare parts, frequent reduction of traffic due to fuel shortages are only part of the problem that led to the introduction of emergency measures by the Republic government.

Significant changes have taken place after the events of October 2000, when the city's new government has opted for the revitalization of the GSP, as a holder of public transport system in Belgrade.

BusPlus is an electronic payment method where commuters load fares on a thin plastic card.

[7] Most of GSP's revenue is still generated through subsidies by the city of Belgrade; in 2017, that amount stood at 65 million euros.

[9] In April 2019, GSP along with the city of Belgrade signed a contract to purchase 244 new buses, of which 70 are manufactured by Turkish BMC and 174 by Chinese Higer.

In April 2023, the City Assembly of Belgrade voted in favour of terminating the contract with KentKart which provided the BusPlus tracking app, as well as fare collection services.

A brand new state-owned enterprise called "Naplata prevozne usluge" was created, dedicated to collecting GSP fares.

While the fares became quite a bit cheaper, this was a controversial decision because the termination of the Kentkart contract meant the BusPlus transit tracking app stopped working, as the city didn't have access to GPS data of individual transit vehicles.

The blue scheme doesn't have the GSP logo, and it replaces with "Beograd" sign, and coat and arms of the city.