Greater Manchester Police is seeking to "recoup" the costs of the delayed implementation of a troubled computer system.
The force is in "sensitive" negotiations with Ernst & Young and Capita regarding the 16-month delay in installing the iOPS system.
The system was widely criticised in a report on Tuesday for causing delays in answering 999 calls and other problems.
Both Ernst & Young and Capita have declined to comment.
The former was the force's strategic developer partner in the project, while the latter provided the software.
Chief Constable Ian Hopkins said: "There have been increased costs of course to put people on overtime to deal with things.
"We had a system that was developed in-house. It needed a lot of software developers and technicians to be able to maintain it.
"We are very clear with the delay where we think there are costs that we should be able to recoup. We are in very sensitive commercial negotiations with our partners."
Mr Hopkins said he could not discuss further details while the negotiations continued.
The police chief also stressed the new system would ultimately save GMP some £500,000 per year.
The watchdog report, published on Tuesday, said iOPS had compromised the force's ability to assess those at risk.
As well as causing a delay in answering 999 calls, it also led to "serious" backlogs in dealing with abuse cases and a loss of staff confidence.
The IT system was installed in July 2019 after being delayed by 16 months due to several technical problems which were "worse than anticipated" during the transition, leading to "reduced force performance".
In February, officers had to revert to using pen and paper during one system upgrade.
However, despite the problems, some police staff told the BBC the new system had some positive attributes.
One call handler said it was much easier to trace emergency callers who were distressed or had rung off.
The HMICFRS report said training issues meant staff had "very little confidence" in a system they did not trust.