The TTC is engaged in a dispute with Metrolinx over millions of dollars in lost revenue from faulty Presto readers.

According to spokesperson Brad Ross, the TTC has billed the provincial transit agency for $4.2 million in revenue that it has lost since January, 2016 but Metrolinx has not yet agreed to pay the claim.

The Toronto Star is reporting that the dispute centres around money that Metrolinx believes that it is owed for Presto work requested by the TTC.

That work includes the installation of Presto readers on older-model streetcars amid delays in the delivery of the city’s new fleet of streetcars, according to the newspaper.

In a statement provided to CP24 on Friday morning, Metrolinx confirmed that there is an ongoing negotiation with the TTC but described the talks as “just a normal part of doing business.”

“There is an ongoing negotiation regarding claims Metrolinx has with TTC for work we’ve done on their rollout and TTC has against Metrolinx for any potential lost revenue,” the statement reads. “During a large technological rollout such as this, with two organizations working together on such a major system upgrade, there will be some accounting matters that need sorting out. We’re doing that now and we are absolutely confident that working together we can resolve it quickly.”

The TTC has said that it hopes to complete its switch to Presto sometime in 2018, at which point traditional fare media including tokens and Metropasses will be eliminated.

Technical glitches, however, have slowed the rollout of the technology to date with both faulty readers and the delayed installation of Presto-enabled fare gates causing issues for the TTC.

According to the statement provided to CP24 by Metrolinx, the reliability of card readers has improved and is now “consistently in the high 90.” The transit agency said it remains committed to ultimately “getting that number as close to 100 per cent as possible.”

Meanwhile, Presto-enabled fare gates continue to be installed at TTC stations. According to a recent report from acting TTC CEO Rick Leary, all entrances at 43 subway stations have been equipped with Presto-enabled fare gates. The TTC has a total of 75 stations.