A system that processes payments for municipal services came back online shortly before 2:30 p.m. after a widespread software outage shut down vehicle registration and tax payments for most of Monday.

About two dozen local governments across Maine were unable to process payments for municipal services for much of the day. Bath, Gorham and South Portland were among the municipalities that could not accept payments.

TRIO, a municipal payment platform from Harris Local Government, went offline around 9 a.m. Monday.

The following cities and towns reported outages: Arundel, Augusta, Bath, Berwick, Bethel, Damariscotta, Detroit, Gardiner, Gorham, Gray, Harrison, Houlton, Jefferson, Kittery (only for vehicle registration), Limerick, Livermore, Norridgewock, Ogunquit, Paris, Rumford, Sebago, South Berwick, South Portland, Van Buren and Wales.

Harris, the software maker, told towns that it needed to address a critical security patch. The software previously went offline in May 2025, said city of Augusta spokeswoman Haley Gauvin. That outage lasted about a day.

The software is used by many local governments in Maine because it has a relatively user-friendly interface, said Augusta City Clerk Kelly Gooldrup.

“When it works, it works great,” she said.

Buxton, Hallowell and Sidney are among the towns that use TRIO but host the software on a local server. Staff at those governments said their offices had not experienced any issues.

Several of Maine’s larger cities, including Portland, Lewiston and Auburn, were unaffected by the outage.