To access the Visa Signature (and Infinite) lounge benefits at London Heathrow (LHR) in 2026, you must use the Visa Airport Companion App. The traditional method of just showing your physical card is no longer supported at most participating lounges. First, you must register your eligible Visa Signature card in the app before you arrive. Once registered, the app will show you which specific lounges you can access; at Heathrow, this typically includes various DragonPass or Priority Pass affiliated lounges like the Plaza Premium or Aspire lounges in Terminals 2, 3, 4, and 5. Depending on your specific bank's agreement, your access may be complimentary or may require a discounted entry fee. You will need to "Redeem" a lounge pass within the app to generate a QR code, which the lounge staff will scan along with your boarding pass. Be aware that some high-traffic Heathrow lounges may require a pre-booking during peak travel seasons, even if your Visa card technically grants you "free" entry.