The rules for checking a bag with airlines can be confusing. It gets even more complicated when you’re connecting between two different airlines. And in 2025, it’s just as tricky if you’re not only flying with two airlines, but on separate reservations.
You’ll see the term PNR, which stands for Passenger Name Record. That’s the six-character code assigned to your airline reservation. Sometimes, several flights—even on different airlines—can be issued under the same PNR. If that’s the case, you should usually have no problems checking bags through, especially if the airlines are in the same alliance. The real complications come when you have flights on separate PNRs.
I’m talking about when you have made one reservation with one airline and a separate reservation for your connecting flight.
The answer to the question of whether or not you can check the bags from your departure airport to your final destination is, well, complicated. This is because there’s a difference between what’s possible, what’s reasonable, and what’s required.
Each U.S. airline has its own rules about interlined baggage. If you need to know what the airlines are expected to do, that’s where to start.
What’s our experience when interlining bags on separate reservations?
We rarely need to book separate reservations, so I have a limited dataset to work with. However, when I’ve needed to do so, my success rate in checking bags from different PNRs has been 100%.
I try to book flights where it should be easy to interline bags, such as sticking to the same airline alliance for all flights. I also usually try to do this when I’m checking in for a business class flight, which has increased my odds of getting a helpful check-in agent.
For instance, our first flight on the way home from Southeast Asia was in Singapore Business Class to San Francisco. From there, I booked separate positioning flights for us to get back to Orlando with United Airlines.
We stayed overnight at Changi Airport and checked in early for our flight. The business class line was empty, and we were met by a cheerful airline agent. I asked if she would be able to check our bags to our final destination, as we had a flight from San Francisco to Orlando on a Star Alliance partner, United.
She asked for the flight information and started typing away. After confirming that our flight on United was in economy, she typed some more. Eventually, she apologized that she had to go talk to another agent and that she’d be back shortly. It took about 10 minutes, but she returned and printed out our boarding passes for our Singapore Airlines and United Airlines flights. I was reminded that we’d have to pick up our bags in San Francisco to go through US Customs and could re-check them without having to stand in line.
We’ve had similar experiences when checking bags with Singapore Airlines connecting to a Lufthansa flight and when flying on separate tickets with Delta and Virgin Atlantic.
Will this work for you?
While our success rate has been 100% when trying this, keep in mind that official airline policies in 2025 have become more restrictive. Whether it works for you may depend heavily on which airline you’re flying and the check-in agent you encounter.
- American Airlines: Will not check bags through on separate PNRs, even with oneworld partners or other American flights. All flights must be on the same reservation.
- Delta Air Lines: By default, Delta will only check your bag to the destination of the first Delta ticket. They will sometimes make exceptions if your second ticket is on a close SkyTeam or joint venture partner (like Air France, KLM, or Virgin Atlantic).
- United Airlines: Will check bags through on separate PNRs only if your onward flight is on United or a Star Alliance partner, and not in Basic Economy. Otherwise, you’ll need to re-check your luggage.
Delta and United have published policies to check bags through if you’re flying with an alliance partner. American’s policy says they will not check the bag through on separate PNRs with partner airlines or even with their own planes.
If you’re going to make two separate reservations, make sure to leave enough time during your connection to plan for the worst-case scenario. That means being prepared to claim your bag, go back to the check-in desk, and re-check it. With American, this is almost always required; with Delta and United, it depends on the partner airline and ticket type. If you’re connecting in a country that requires a visa for entry, this can become a serious problem—so in those cases, paying a little more to book everything on the same PNR is worth the peace of mind.
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