The MBTA's fare vending machines were not accepting credit or debit cards, leaving riders to use cash to ride public transportation on Thursday morning.
"We apologize for the inconvenience and are working to fix this as quickly as possible," the MBTA said on Twitter around 8:30 a.m.
Service was restored before 10:30 a.m.
An MBTA spokesman told the Boston Globe technicians were working to fix the issue.
No further information was immediately available.