Whether to fly on one ticket or separate airline tickets?

One comment I see frequently is how travellers can save money by buying separate tickets to cover their flights. Eg instead of say (made up example) USA to Prague on one ticket, buying one ticket for flights between USA and London and another for flights between London and Prague.

While it is true that separate tickets can save money, in some cases a lot of money, over buying a single air fare, there are some downsides that most people gloss over. Even if it costs more to fly on a single ticket it can be worthwhile doing so.

4 advantages of using a single ticket

• Protection for misconnection. If the first flight is so late that you miss the onward flight then the airline has to find another way to get you to your destination. This is the biggest advantage.
• Protection in the event airline schedules change materially. If you have separate tickets and the schedules change to force a misconnect, then it is up to you to find a solution which will likely cost money to change one or both of those tickets. When travelling on a single ticket the airlines have to find an alternative that does not misconnect. Airlines change schedules frequently (and this year more than most due to plummeting travel demand).
• Ability to through-check bags to the final destination. When flying on one ticket you can check your bags through to the final destination, whereas on separate tickets you might be able to or may not ... at the airline's discretion. Note you may still need to collect bags and take them through customs at some intermediate airports.
• Better service in the event checked bags get lost. If the airlines temporarily lose or delayed delivery of a checked bag they have an obligation to deliver it to you at your destination (airport at a minimum). On separate tickets this is your transfer point not your final destination, thus it may take further time, money and inconvenience to get your bags back.

Misconnection costs

As alluded to above, misconnections on separate tickets can be very costly. You may have unexpected accommodation costs at the transfer city. The second ticket may have been voided by your no show (ie failure to check in or board in time), thus requiring a purchase of a new ticket at a high walk-up fare (or rebooking fees for a flexible fare). There may be no flights scheduled or with space available for some days, causing a lengthy delay and further costs.

In other cases a misconnection may be almost costless. If the second ticket is flexible, there are frequent later flights and these are not full the impact may be merely a delayed arrival.

7 ways you can manage misconnection on separate tickets

Despite the potential costs and risks, I often do travel on separate tickets - up to half a dozen on a single trip (albeit with a complex itinerary). Here are some ways to reduce the risk of misconnecting, and mitigate the effects if you do misconnect.

• Build in lengthy connection times. Take the time you think you need to transfer on a bad day, allowing for check-in requirements for the second ticket, and add a healthy margin. Add some more time to allow for possible schedule changes. A large buffer if travel is far in the future (more opportunity for change), or if there are few alternatives (if a route is currently 3 flights a week and could change to 2 a week you may want to allow for a day or two at the transfer in between tickets). On some of my more complex tickets I may build in a stopover once a week purely to allow room to get back on schedule if I have a compounding misconnection.
• Travel light. With carry-on only you have more options to fly standby or make last minute flight changes. It also allows you to check in later than with checked luggage in some circumstances. If your carry-on luggage is not too heavy, running for the onward flight may be the difference between making it and not.
• Use online check in. In conjunction with no checked bags this may enable you to simply arrive at the gate when the onward flight is boarding. Compare this to a need to check in at the airport and deposit bags, both of which have a cut-off well before departure.
• Buy tickets that are as flexible as possible/affordable. Higher fare classes give more options to switch flights than cheap fares. This may negate the benefit of cheaper separate tickets though.
• Have frequent flyer status with the airline(s). This helps speed processing at the airport check-in and possibly security. Some airline agents may be more willing to try checking you in late or rerouting - ie bending or waiving some of the rules.
• Where possible have a back-up routing or flight options. Perhaps you could switch from an indirect to a direct route if there is a problem? Eg I switched from San Francisco to Seattle via Portland to a direct flight when weather in San Francisco caused long delays meaning I'd misconnect at Portland. I was able to do this because my tickets were flexible enough and I had high frequent flyer status with the airline.
• Be prepared to walk away if it goes really bad. A year ago the big storm that hit San Francisco caused delays of many hours. I was booked on Virgin America for a day trip Los Angeles to San Francisco return, and that night flying to Sydney on United on a separate ticket. Rather than risk misconnecting and losing a day (no later flights to Sydney), I opted to cancel my Virgin America ticket and stay in Los Angeles until my evening flight out. The consequences of missing the onward flight were worse to me than missing a day in San Francisco.

Is a single ticket better than separate tickets?

The answer is it depends. In some situations it is and others it is not. Only the person flying can weigh it up. Consider the risks of separate tickets, and the consequences if something goes wrong. The points above are some of the main factors and hopefully will assist readers in making their own decisions.