Yes, in 2026, it is highly mandatory to complete the online check-in process for almost every major cruise line (such as Royal Caribbean, Carnival, or Disney) before you arrive at the port. This process usually opens 30 to 45 days before sailing and requires you to provide passport details, emergency contacts, and a credit card for onboard expenses. More importantly, this is when you select your "Arrival Time Window." Modern cruise terminals operate on a strict schedule to manage crowds; if you show up without having checked in online, or if you arrive outside your assigned window, you may be forced to wait outside the terminal for hours until a slot opens up. Completing the process online also allows you to upload a security photo and print your boarding pass and luggage tags at home, which significantly speeds up the physical boarding process. If you fail to check in online by the deadline (usually 2 to 3 days before the cruise), you might even be denied boarding, as the cruise lines are required by law to submit their final passenger manifests to government authorities well in advance of departure.