I am traveling on United Airlines to Munich and then connecting to LuxAir. Will my checked in luggage be automatically transfered to the LuxAir flight or do I have to do it myself?
I find this astonishing, but it seems the answer is no.
According to the computer reservation system, United Airlines has signed interline baggage agreements with the following airlines:
MAY CHECK BAGGAGE TO AA AB AC AF AH AI AM AR AS AV AX AY AZ A3 BA BB BE BI BR BT BW CI CM CO CS CX CZ DL EI EK EN EQ ET EV EY FB FI FJ FM FV FZ GA GF GK G3 HA HO HP HU HX H2 IB JJ JL JO JP JQ J2 KA KC KE KL KM KQ KS KU KX LA LH LO LP LR LW LX LY MD ME MF MH MI MK MQ MS MU MX NH NU NX NZ OA OK OM OO OS OU OV OZ PG PK PR PS PX PZ QF QR RJ RO SA SK SN SQ SU SV SZ S2 S7 TA TG TK TP T0 UA UL UN UP US UX VA VN VS VW WM WP WY XF XL ZH ZK 2K 3K 3M 4M 4Q 4U 7H 9K 9W
As you will see, LG (Luxair) is not in the list. Therefore even on the same ticket, the baggage cannot be through-checked.
(The reason baggage interline agreements are needed is that, in international law, both the first and the final carrier in the baggage journey are both equally liable to the passenger for any defect or loss in the baggage on arrival. Therefore you may sue Luxair even though United lost the bag. Therefore how the liability is apportioned between them must be decided before the final carrier agrees potentially to take responsibility for the first carrier losing the bag.)
In the event you do manage to get this through-checked, I would be interested to hear about it!