Users of Mitro will have until August 31 to find a new password manager, with the service set to shutdown due to the cost of keeping the lights on.
The announcement comes twelve months after Mitro was acquired by Twitter for an undisclosed amount.
"We have been maintaining Mitro in our spare time, using our own money," Mitro said on its website. "At this point, the cost and administrative burden has become too much. We do not have time to properly manage a service that people rely on for their security. As a result, we need to stop running it."
From July 18, the ability to create new accounts will be turned off, with the service set to read-only mode on August 16, before the shutdown date of August 31. On September 13, Mitro said that all user data will be "permanently destroyed".
At the time of its acquisition, Mitro open sourced its server and client software, with the project seeing little activity since the start of the year.
Mitro has recommended that users export their data and move to one of 1Password, Dashlane, or LastPass.
Last month, LastPass suffered a data breach. At the time, LastPass chief executive Joe Siegrist said that encrypted user data was not taken, and the company had not seen any user accounts being accessed as a result of the breach.