A first in the history of the FIFA World Cup, the service allows fans to enjoy two matches on the same day, the company said, adding in a video message that the initiative involves some 580 buses.
Karwa has mobilised its fleet with specialised technical teams to ensure a comfortable and smooth transportation experience during the tournament.
Fans from around the world lauded the initiative.
Overall, about 4,000 buses are being operated during the tournament, of which some 3,000 are dedicated to transporting fans, including more than 800 fully electric buses that operate with zero carbon emissions.
Meanwhile, a total of 3,168 buses were used to transport 284,851 fans on the 11th day of the tournament - Wednesday. The buses made 9,663 trips.
According to figures released by the Ministry of Transport (MoT), a total of 8,646 passengers were transported by the Education City and Msheireb trams, while the number of people ferried by the Doha Metro and Lusail Tram on the same day stood at 761,635.
The MoT also said 948 aircraft movements were recorded at Hamad International Airport and Doha International Airport on Wednesday.