The Florida Department of Transportation announced today that it will suspend all payments to the SunPass contractor until the electronic tolling system is fixed.

In a letter sent to the president of Conduent State & Local Solutions, Inc., David Amoriell, FDOT secretary Mike Dew acknowledged that the vendor has made some improvements on processing transactions and customer service technology. But he said that Amoriell's assurances in a letter last week that Conduent (a Xerox Corp. spin-off) would fix the system aren't enough to satisfy the original performance-based contract signed in 2015.

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"Because this is an absolutely critical service, the Department will not deem the assurances Conduent provided in your July 10 letter to be adequate," Dew wrote.

He called on Conduent to consistently process current transactions on time and post them to the correct user accounts, process the backlog of more than 100 million unprocessed charges, and give the state a financial record of each day's activity.

"Late fees and penalties will not be imposed until the system is fully operational and is providing the benefits and ease of access that SunPass customers deserve and expect," FDOT spokesman Ed Seifert said in a news release.

Florida transportation officials say Conduent is expected to process at least 8 million backlogged charges each day, which is reportedly about two days' worth of charges, according to WTSP-Ch. 10.

But the vendor isn't meeting that goal. Last Wednesday, FDOT said in a press release that 28 million backlogged transactions had been processed. As of today, five days later, 46 million more transactions had been processed — which lags behind the daily agreement by 22 million.

The original 1600-page contract between Xerox (now Conduent) and FDOT included a "payment schedule" based on percentages — without specifying amounts or a timeline. In a December 2016 audit, the state's Department of Financial Services found this to be a problem. The audit also criticized the state's contract for failing to detail what services Xerox would have to provide before it was paid.

FDOT officials responded to the audit, saying that the agency uses a "monthly scorecard" to analyze the contractor's performance. The Department of Financial Services determined that it still wasn't enough.

Florida transportation officials signed the original seven-year contract worth $287 million with Xerox in November 2015 and later increased the deal to a total of $343 million. FDOT has paid the company almost $77 million, according to estimates on Chief Financial Officer Jimmy Patronis' website.

Conduent has a history of failing to process toll charges in at least seven other states, with a baggage of drivers receiving bills for thousands of dollars in late fees, ensuing lawsuits, audits, state fines against the company and amnesty programs. As the Tampa Bay Times reported on Sunday, Florida transportation officials knew about its troubled past when they signed the contract.

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Contact Hannah Denham at hdenham@tampabay.com. Follow @hannah_denham1.