The Steam Packet Company says it can only accept cash payments on vessels today.
It posted to Facebook earlier, saying it was having problems caused by worldwide IT issues.
In its post, it says all sailings on the Manxman and Manannan are affected.
Problems with software from IT giant Crowdstrike have been causing difficulties around the world today.
Northern bus services to be raised in Keys
Ben out of service for maintenance work this week
Richmond Hill closed again tonight for work
October warmer and sunnier than usual, says Met Office
MHK queries cost of Liverpool awards trip
DOI says it has 20 empty public sector homes
Marquee plan submitted by Milntown Estate
Fire crews called to free driver from crashed car