This is a generic question, but first my specific situation.

I want to fly from Maputo, Mozambique (MPM) to Portland, Oregon (PDX). The cheapest flight I can find online for this itinerary is about $5,765. If I change my departure from Maputo to Johannesburg, South Africa (JNB) then the cheapest flight to Portland on the same days is $2,029.

Johannesburg is only about an hour away from Maputo and a round-trip flight that could connect to the second itinerary costs $470 meaning that I think I should be able to get a total price of around $2,029 + $470. However, no matter what I try on a variety of different sites I cannot even get this itinerary to appear. Because of the risk of missed connections and the necessity of re-checking bags I don't want to buy two separate tickets.

Is this simply a limitation of the online sites that can't produce more complex or unusual routes? I asked a travel agent to price this itinerary, but they gave me a completely different and more expensive schedule and told me they could not price the itinerary I wanted. Is it really possible that some routes cannot be booked even though the schedule would be valid?

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    Did you try asking a travel agent to book this route for you? They have access to a lower-level booking system than most websites offer. Commented Jun 27, 2012 at 9:19
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    if A->B->C is in one flight. sometimes you can book A->B and A->C but not B->C. This happens if B and C are in different country(s). Commented Jun 27, 2012 at 9:25
  • Maybe your JNB-Maputo with that airlines is B->C.. Commented Jun 27, 2012 at 9:27
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    @hippietrail Yes, I asked one travel agent to price the exact itinerary and they said they couldn't do it....
    – user27478
    Commented Jun 27, 2012 at 9:39
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    On which date do you want to fly? I can find one way flights from Maputo to Portland, OR with Ethiopian Airlines for USD1,520. Commented Jun 27, 2012 at 10:33

2 Answers 2


What you're most likely hitting up against here is "Interline agreements" (not to be confused with Interline baggage).

When you book multiple flights on a single "ticket", even when the flights are on multiple airlines, the ticket is issued by a single airline. eg, if you say SFO-JFK on United, and then JFK-LHR on British Airways, the ticket will be issued by either United or BA. Note that this is different to code-share flights - the flight numbers will still be the correct airline codes, and the entire process will be basically invisible to the customer, it's just down to who actually sells you the ticket.

They can do this because United and BA have "interline agreements" with each other, which means that they can sell flights on each others airlines. That's not to say that they want to do this (United would prefer you flew JFK-LHR with them!) so it may not be possible to do it (for example) via their website - but they can do it.

Sometimes interline agreements are one way. For example, Continental used to be able to sell flights on Jetstar, but Jetstar could not sell flights on Continental.

To make it even more confusing, sometimes airlines will only allow certain fares to be sold via interline agreements, and/or only allow those fares to be sold for departure from specific countries (eg, for an itinerary originating from JNB they are available, but not for an itinerary originating in MPM)

As a very broad statement, most of the major airlines have interline agreements with each-other, whilst most low-cost carriers do not have interline agreements with anyone!

In your case, most likely the airline that flies the Maputo to JNB flight does not interline with the airline that flights JNB-PDX so you can't purchase them on the one ticket. The higher priced fare you're getting it probably on a different airline, or if not at least a different fare class. Sometimes the only option is to take the risk and buy two tickets (potentially backing it up with travel insurance in case of any problems!) or change your schedule to fly into the connection city much earlier - possible even the day before.

Sometimes trying a different website/booking engine will help, as this might change which airline the ticket is issued by. eg, instead of booking the ticket against the airline that flies JNB-PDX, with MPM-JNB being done via an interlined airline, it might be booked against the airline that flies MPM-JNB, with JNB-PDX being booked via the interline agreement.

  • That makes sense. When I add the Maputo-Joburg connecting flight, the route and airlines from Joburg to Portland changes completely and I can't even find the original cheap Joburg-Portland schedule.
    – user27478
    Commented Jun 28, 2012 at 6:24
  • One question, in the case of more than two airlines, do they all need to have interline agreements with each other. How does that work?
    – user27478
    Commented Jun 28, 2012 at 6:26
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    No, just whichever airline issues the ticket. They will need to have an interline agreement with ALL of the other airlines on the ticket.
    – Doc
    Commented Jun 28, 2012 at 6:39
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    I noticed on Wikipedia's page about interlining en.wikipedia.org/wiki/Interlining this quote "Normal fare construction rules state that an international ticket should be issued on plated on the first international carrier." Since the carrier from Maputo to Johannesburg (LAM) is pretty minor I suspect it may not have many interlining agreements which probably explains the phenomena I'm seeing.
    – user27478
    Commented Jun 28, 2012 at 12:31
  • and of course many booking sites simply don't have a contract with all airlines so you may not see all available options. Best to always dig around and look at airline sites directly, also avoids often hefty booking fees and stuff added on by those booking sites that you may not want.
    – jwenting
    Commented Jul 16, 2019 at 3:42

It's not atypical for online booking engines to not be able to book across any combination of multiple carriers. And, obviously, if the carrier for Maputo To Joburg isn't bookable online, you will have a hardtime to find an online booking for it.

That said, here's an example round trip for 1792 USD:


  • Actually, Maputo-Joburg is bookable online I'm just not able to book it together on same ticket as Joburg-Portland
    – user27478
    Commented Jun 28, 2012 at 6:23
  • The link I supplied above in this answer is a ticket for the journey from Maputo to Portland.
    – MastaBaba
    Commented Jun 28, 2012 at 6:27
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    You didn't refrain from not using a lack of double negatives (-; Commented Jun 28, 2012 at 7:24

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