# Question: Second level interlining

Imagine a mainline carrier that has a regional subsidiary. Mainline carrier (let's call it 123 air) has interline with a 3-rd party carrier (let's call it ABC Air) and a regional subsidiary of 123 Air (let's call it 123 Connect).

123 Connect operates links to a focus city "F" from cities X, Y and Z

123 Air operates links between a hub "H" and other cities including a focus city "F".

ABC Air operates international links from ABC Hub into 123 Air Hub "H"

It looks like this:

X <----> F <====> H(ub 123 Air) <********> ABCHub

<---> is 123 Connect flight

<==> is 123 Air flight

<***> is ABC Air flight.

Now we now that 123 Air has interlines with both its regional subsidiary 123 Connect and with ABC Air international.

QUESTION:

Would 123 Connect need to have interline with ABC Air as well, in order to get passengers from ABCHub ****> H ===> F ----> A (basically for F -> A leg)

We know that ABCHub *****> H ====> F is covered by interline between 123 Air and ABC Air.

The question is whether passengers would get booked on F----> A leg based on 123 Air and 123 Connect interline agreement, or based on ABC Air and 123 Connect interline agreement?

It is important to note that 123 Connect operates only to/from Focus city "F", where it hands over pax traffic to 123 Air, which brings it to hub where it interlines with other carriers. ABC Air has no flights to/from focus city "F", from which 123 Connect operates. ABC Air has only flights to hub city "H" form which mainline 123 Air operates.

Thank you!

Imagine a mainline carrier that has a regional subsidiary. Mainline carrier (let's call it 123 air) has interline with a 3-rd party carrier (let's call it ABC Air) and a regional subsidiary of 123 Air (let's call it 123 Connect).

123 Connect operates links to a focus city "F" from cities X, Y and Z

123 Air operates links between a hub "H" and other cities including a focus city "F".

ABC Air operates international links from ABC Hub into 123 Air Hub "H"

It looks like this:

X <----> F <====> H(ub 123 Air) <********> ABCHub

<---> is 123 Connect flight

<==> is 123 Air flight

<***> is ABC Air flight.

Now we now that 123 Air has interlines with both its regional subsidiary 123 Connect and with ABC Air international.

QUESTION:

Would 123 Connect need to have interline with ABC Air as well, in order to get passengers from ABCHub ****> H ===> F ----> A (basically for F -> A leg)

We know that ABCHub *****> H ====> F is covered by interline between 123 Air and ABC Air.

The question is whether passengers would get booked on F----> A leg based on 123 Air and 123 Connect interline agreement, or based on ABC Air and 123 Connect interline agreement?

It is important to note that 123 Connect operates only to/from Focus city "F", where it hands over pax traffic to 123 Air, which brings it to hub where it interlines with other carriers. ABC Air has no flights to/from focus city "F", from which 123 Connect operates. ABC Air has only flights to hub city "H" form which mainline 123 Air operates.

Thank you!

In your case 123 Connect does not need an interline agreement with ABC as passengers come to F with 123 Air and they have an interlining agreement

Don't think too complicated. Passenger will transit as long as the current carrier is partner with the next carrier. So in your case, as long as 123 interline with both region and partner airlines, then the flight is valid.