You can update your arrival information in the SG Arrrival Card e-service via 'Update a Submission', provided the record has not expired. Please note that the arrival information you have submitted for each trip will expire:-
i) after the date of the arrival; or
ii) after you have made your trip, whichever is earlier.

If you are using MyICA Mobile App, you can update your arrival information, provided the record has not expired, by navigating to your trip record and select the 'Edit' button to make the changes. You can tap on the 'Submit' button after making the amendments.

This information is sourced from ICA