For solo travelers, they also have to pay an additional charge to occupy the room alone, for the 'privilege' of not having to share with someone else. This charge often means a solo traveler will pay the same, if not more, than the price of two people sharing. This is known as a single supplement.

A "single supplement" is an additional surcharge that cruise lines apply to a traveler who is booking a double-occupancy cabin alone. Because most cruise fares are priced based on "per person, double occupancy," the cruise line stands to lose money on onboard spending (like drinks and excursions) if only one person occupies a room meant for two. This supplement can range from 10% to a staggering 100% of the standard fare, essentially forcing a solo traveler to pay nearly double. In 2026, however, many lines like Norwegian, Royal Caribbean, and Virgin Voyages have started adding "Studio" or "Solo" cabins that bypass this fee entirely. If you are a solo traveler, the best way to avoid the supplement is to look for "No Single Supplement" promotions or to book with a line that specializes in solo travel by providing dedicated cabins with smaller footprints but no extra "penalty" fees.