Originally believed to affect about 2,000 customers, the Long Island Rail Road announced Tuesday more than 19,000 commuters might have been double billed by its ticketing machines.

LIRR told News 12 Long Island last week that on October 1, a computer glitch caused automated ticketing machines to charge 2,000 customers' credit cards twice.

Tuesday, officials said at least 19,000 customers might be affected by the problem, which they said was caused by the installation of new software. Additionally, the problem occurred not only on October 1 as originally thought, but from September 25 until October 8.

LIRR said it would automatically credit individuals' accounts. Anyone with questions can contact LIRR at (877) 547-7876.