So, you couldn't be flying on, say, Southwest Airlines, and still be able to enter just because you paid for membership. But soon, you must buy pricier tickets to get into the lounge, even with membership. As of Feb. 2, 2023, Delta Sky Club members flying on basic economy tickets cannot enter.

No, you generally cannot use the Delta Sky Club if you are flying Southwest Airlines. As of the updated 2026 rules, Delta has strictly enforced a "same-day Delta flight" requirement for lounge access. This means that even if you have a premium credit card like the Amex Platinum or the Delta SkyMiles Reserve, or if you hold a paid Sky Club membership, you must present a boarding pass for a Delta-operated or Delta-marketed flight (or an eligible partner like Virgin Atlantic or Air France) to enter the lounge. Southwest is not a Delta partner, nor is it part of the SkyTeam alliance. Even the "per-visit" pass options that were once available to certain cardholders have been restricted to those traveling on Delta. If you are flying Southwest and desire lounge access, your best options in 2026 are to use a Priority Pass lounge (if available in your terminal), visit a Centurion Lounge (if you have an Amex Platinum), or look for a "pay-per-use" independent lounge like The Club, which does not require you to fly with a specific airline.