Yes, British Airways (BA) lounges in 2026 maintain a "Smart Casual" dress code, though it is generally enforced with "polite discretion." High-value "Gold" and "First" lounges are the most strict; you are expected to avoid "scruffy" items like torn jeans, "gym-only" attire, or offensive slogans. In the Concorde Room, the standard is even higher, with many travelers opting for "Business Casual" to match the high-end environment. A peer-to-peer "win" for 2026: while "Smart Sneakers" and clean, dark denim are widely accepted, wearing flip-flops or being "shirtless" is a non-negotiable "no." The goal of the dress code is to maintain a high-value, relaxed atmosphere for all guests. If you look like you are heading to a "Five-Star" hotel lobby, you will have no issues. If you look like you just finished a high-intensity workout or are heading to the beach, you might be gently reminded of the "Lounge Etiquette" by the desk staff before you are allowed to enter.