Most banks are facing a costly switch that could put customers at risk if nothing is done. Roughly 95% of all U.S. ATMs use Windows XP, which will be phased out April 8, along with its current security updates.

The software upgrades have to be completed one machine at a time. There are currently 200,000 ATMs across the country.

Citibank and Wells Fargo confirmed they are updating their machines, but would not release any further information. JP Morgan Chase is planning to work on their ATMs in July, and because of the delay, the company worked out a deal to use Windows XP for one more year.

However, many older machines like the ones in bars use a former version of Windows that is still supported by Microsoft.