Gate card: Lufthansa (LH)

The airline's policy: “Free Neighbour Seat”

Lufthansa has no mandatory customer-of-size rule published; instead it 'recommends' booking the vacant seat next to you (Free Neighbour Seat) if: you want more personal space; you cannot be seated in a single seat due to your physical build; you are unable to fold down both armrests; or you cannot fasten your seat belt despite the use of a single seat belt extension. The adjacent seat is then guaranteed to remain empty. Available on continental and intercontinental routes.

Refunds: Not published for the extra seat specifically. Lufthansa's general seat-reservation refund rules cover cancelled flights/rebookings where the seat category is unavailable; no published guarantee of a refund if the flight departs with empty seats (unlike Air France).