Princess Cruises is the latest major cruise line to offer passengers the chance to bid for discounted cabin upgrades online after booking, part of the cruise line’s newly introduced Princess Upgrade program launching next month.As of Sept. 6, Princess cruise passengers will have the opportunity to bid for upgraded rooms for upcoming trips, ranging from those with an ocean view or private balcony to larger suites, the California-based line announced Thursday.“Upgrading is a popular request from our guests and we’re pleased to deliver a process that lets them improve their stateroom category by making an offer that fits their budget and lifestyle,” Princess president John Padgett said in a statement.For more TPG news delivered each morning to your inbox, sign up for our daily newsletter.(Image courtesy of Princess Cruises)Initially, only travelers on the line’s five North America-based ships — Caribbean Princess, Discovery Princess, Enchanted Princess, Regal Princess and Ruby Princess — will have the chance to participate in the newly launched upgrade program. It will be expanded to the rest of the fleet by November.To participate in the Princess Upgrade program, passengers should look for an email invitation sent once they have made their final payment and the payment deadline has passed. The email will prompt them to submit a bid on any room category above the room type they originally booked.With Princess Upgrade, guests can bid to upgrade at a discounted rate to any category of room with availability, including rooms with picture windows or deluxe balconies, minisuites and even full suites. There is no minimum bid price, a Princess spokesperson told TPG in an email.Passengers can also bid for multiple rooms to increase their chance of success, but they can only win one bid and will only be charged once for an upgrade. After guests submit their bids, they can cancel or change them at any time before one is accepted.Bids are based on two passengers in one cabin. If a bid is accepted, any additional guests booked into the same cabin will be upgraded for free.Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.Princess Upgrade will give passengers the opportunity to score a nicer cabin for less money than they would have spent on booking a higher cabin class in the first place. However, it will not preclude travelers from getting upgrades in other ways, a Princess spokesperson said. These could include booking a room during a “free upgrade” sale or paying the fare difference for a nicer room after the initial booking.Read more: How to get a free or cheap cruise ship cabin upgradePrincess is not the first cruise line to let passengers bid for upgrades. Norwegian Cruise Line, Royal Caribbean, Celebrity and MSC Cruises already have similar programs in place.If for some reason a guest does not get an invitation to upgrade via email, they can initiate the process directly through Princess Cruises’ website starting Sept. 6.Planning a cruise? Start with these stories:The 5 most desirable cabin locations on any cruise shipA beginners guide to picking a cruise lineThe 8 worst cabin locations on any cruise shipA quick guide to the most popular cruise lines21 tips and tricks that will make your cruise go smoothly15 ways cruisers waste money12 best cruises for people who never want to grow upThe ultimate guide to what to pack for a cruise