Zupco is now hiring conventional buses for $4 000 a day and kombis for $1 000 a day, a 33 percent rise in fees, after the Ministry of Local Government and Public Works approved the increases after costing operations.
The hire charges have been backdated to March 1.
Zupco's fleet and franchise buses are used to run subsidised services.
In a letter on May 19, the ministry said: "Following a request by transport operators to have an upward review of the daily hire rate based on a meeting held between them and Zupco, the ministry carried out costing of the bus and omnibus operations.
"It was established that the cost of operation, that is maintenance, tyres and statutory costs had increased by 140 percent, on average, compared to December 2019.
"The request tabled by operators proposed to increase bus hire fees from $3 000 to $4 000 per day and that for commuter omnibuses (kombis) from $750 to $1 000 per day, effective 1 March 2020.
"The ministry recommends these proposed daily hire rates for consideration. We have attached to this minute a letter from Zupco proposing the daily hire rates."