Same flight - different flight number?
 

I booked a roundtrip flight from Frankfurt, Germany to Nashville, TN. On my return flight, I will be bringing my little sister with me. This plan was formulated after I purchased my tickets. I called the travel agency to get her on the same flight as me and they said that they have. However, her flight number is different than mine and I am wondering if it is the same flight. My flight number is KL6142 and hers is DL142. I know that the KLM flight is operated by Delta, but does this mean that it is the same flight? I just want to double check before paying for her ticket. Any comments would be helpful!

welcome to ft. that is most probably a code share. i am not famaliar with delta code shares, but lh and ua do a lot of code sharing. the 3 digit number is usually the filght number of the airline doing the flying. the 4 number is that of the airline sharing the flight. those are not hard and fast rules. some airlines when codesharing use completely different numbers for the same flights. you can usually get a pretty good conficence by checking the flights to the city pairs on orbitz.

Welcome to FT, peachessnc!

There's no direct flight from Nashville (BNA) to Frankfurt (FRA) so the flight you refer to (KL6142) is from Detroit (DTW) to FRA and as you say is operated by Delta. If you do a Google search for KL6142 the first hit will take you to http://www.flightstats.com/ where you will see:

(KL) KLM 6142
(DTW) Detroit, MI, US to (FRA) Frankfurt, DE
Operated by (DL) Delta Air Lines 142

So, yes KL6142 and DL142 are the same flight. I tried to check Delta's website but the response was so slow I had to give up.