You can generally upgrade to any card within the same family, but you'll want to keep in mind that the United Club Infinite card comes with a minimum credit limit of $10,000 as it's a Visa Infinite card, while the United Quest card and United Explorer card require a minimum credit limit of $5,000 as they're Visa ...

Yes, you can typically upgrade to the United Club℠ Infinite Card if you already hold an existing United MileagePlus® credit card issued by Chase, such as the United℠ Explorer Card or the United Gateway℠ Card. This process is known as a product change. To be eligible, your current account must generally have been open for at least 12 months due to CARD Act regulations. Upgrading is a popular choice for travelers who find themselves frequenting airports with United Club locations, as the Infinite Card includes a full United Club membership (valued at $650+) as a standard benefit. When you upgrade, you usually bypass a new "hard pull" on your credit report, but you also typically forfeit the sign-up bonus that a new applicant would receive. It is important to call the Chase customer service number on the back of your current card to check for specific "upgrade offers," as the bank occasionally provides bonus miles for moving to a higher-tier card. If you are a high-volume traveler, the $525 annual fee is often offset by the lounge access, two free checked bags, and 4x miles on United purchases.