Originally Posted by
supermasterphil
Why can't US check him in also for the LH flight? In that case I'd online check in with LH which is possible within 23h of flight.
At the gate for the LH flight, show them your BP and ask if they have loaded your luggage on the second flight. This information is usually connected to your BP...
US often won't issue a boarding pass for LH flights. I don't know why this is, being a Star Alliance flight, but I've had this happen more than once. US will, however, tag the luggage all the way through. Then you can do one of two things in FRA...
Go to a connections desk and have the agent issue a BP and associate it with your luggage receipt or check in online and marry it up at the gate. I've done it at the gate but the agent made me stand to the side and wait until they've boarded all other pax so she could concentrate fully on marrying my bag check number to my BP, so if you want overhead bin space, better do it before showing up at the gate