JetBlue Airways doesn't typically have a physical, walk-in office in Frankfurt for public services like ticket sales instead, you'll use their online resources or call their customer service, often via numbers provided by third-party sites like +1-866-829-1086 or their U.S. line (1-800-JETBLUE) for booking, changes, or support for flights to/from Frankfurt. For airport-specific info, check Frankfurt Airport (FRA) website or Skyscanner for details on terminals for JetBlue flights.
