People travelling by sea are being advised to carry identification with them "just in case".
The Steam Packet has made the plea - but confirmed it does not require people to present ID before they travel.
However the company says other authorities may want to see it following a terror attack in Manchester on Monday which saw the UK's terror threat level raised to critical.
As a result of this some police services at ports - including Heysham - are conducting additional security checks.
Chief executive Mark Woodward is also asking passengers to allow extra time for security and says it would be "sensible" to carry ID as a precaution.
YouTube channel features Island's hand dryers
Snow and ice warning for Mountain Road
No plans for self-driving car laws, says minister
Pulrose 'Escobar' to spend more than 15 years in prison
Two Manxman sailings cancelled
Children 'left at risk' after new law adjourned by MHKs
Commissioners issue plea to dog owners over fouling
Section of TT course to shut for this weekend