Buffer Between Flights On Separate Tickets: What’s The Sweet Spot?

OMAAT reader Peter asked me a question that I think is worth addressing more broadly — if you book an itinerary that involves two or more separate tickets, how much of a buffer should you leave between flights on those two tickets?

There’s not going to be a “one size fits all” answer, but I’d like to share my thought process, and hear how others approach this. First let’s talk about why you might want to book tickets this way, the things I’d factor into deciding on a buffer, and the approach I take (admittedly I don’t always get this right!).

Why you might book an itinerary on separate tickets

Typically, most people will book an itinerary between their origin and destination on a single ticket, even if multiple airlines are involved (which is possible thanks to partnerships and interline agreements). However, there are definitely situations — especially in the miles & points world — where you might want to book separate tickets:

• Maybe you only found reasonably priced award tickets out of a long haul gateway city, and then you need to position there on a separate ticket
• Maybe you’re being savvy and are trying to avoid the UK Air Passenger Duty, so you book your first flight out of the UK separately as a short haul ticket, and then pick up your long haul ticket elsewhere
• Maybe an itinerary just ends up being cheaper if booked as two separate tickets, whether you paid with cash or points
• Maybe you booked a ticket far in advance, but then your plans change, though the most economical option is to just book a separate positioning flight, but still take your originally booked ticket

Anyway, I do end up booking itineraries as separate tickets with some frequency, and the most common reason is because I’m redeeming points out of another gateway city, and that ends up being the most economical option.

The considerations with deciding on what buffer to leave

To state the obvious, there are many factors that would impact my decision of how much of a buffer to leave between flights on separate tickets. For example, if you’re flying a once daily flight to board a cruise or to attend a very important business meeting, I’d take a different approach than if you’re connecting to a ticket in a market that has 50 daily flights.

So to expand on that a bit, here are the things that I’d take into consideration:

• How important is it to actually make the flights on your second itinerary, and to arrive at your destination on-time?
• How flexible are your tickets? If you miss your second itinerary, is it a “use it or lose it” situation, or could you easily rebook?
• Are you checking bags? Obviously you’ll want to add to your buffer if you are, especially since bags often can’t be checked through on separate tickets
• What time of day is your first flight? The earlier you fly, the better the odds of things going smoothly
• What are the weather conditions to consider? On summer afternoons you have to be worried about thunderstorms, and in winter, consider how likely a snowstorm could be
• How many other flights are there that could get you to your destination within a reasonable timeframe, assuming you miss the originally booked one?
• How skilled are you at managing your own travels? If you’re very resourceful and not stressed out by a potential misconnect, you can handle this differently than someone who gets really stressed in these situations

How I decide on how much of a buffer to leave

It goes without saying that if you want to maximize your odds of not having any major disruptions, you should leave a massive buffer between separate flights on itineraries. It’s definitely a best practice to maybe even leave a day between separate itineraries, or at least to leave an unpleasantly large number of hours.

That being said, I want to be realistic here:

• Often people have limited vacation, so adding an extra day enroute might not be practical, might significantly add to the expense of the trip, etc.
• Of course leaving a really long layover sounds smart, but most people don’t want to spend 10 hours at an airport waiting for their connecting flight

Let me share my approach, acknowledging of course that I don’t always get this right (including recently!). As I view it, I take a calculated risk, trying to find the middle ground between minimizing risk and being efficient.

Obviously it depends on the circumstances, but assuming that I don’t 100% have to be at the destination exactly at my planned arrival time, my most common approach is to typically leave a buffer of four hours, and/or to have at least another flight between my original flight and subsequent one that I can be rebooked on, in the event that it cancels.

Admittedly this isn’t a perfect system, and a lot can still go wrong. After all, “when it rains, it pours” also applies to aviation. Sometimes there’s just a very bad weather system, and you have flights for an entire afternoon delayed by hours. In those situations, there’s nothing you can do.

To get a bit more specific, personally I generally hope for a bit bigger of a buffer if I’m checking bags, and if my second ticket is non-refundable or non-changeable. Meanwhile if I’m traveling alone, I’m on separate tickets, or it’s in a high frequency market, I’ve certainly booked connections way shorter than that.

Just to give an example, maybe I have an award ticket booked from Frankfurt to Chicago on Lufthansa, and then I book a connecting flight to Miami on American. There I’d gladly book a short connection, and worst case scenario, I can just rebook on another flight. That’s an example of a low risk situation, as I see it.

I generally view things as lower risk if they’re at the end of my trip, and if I’m headed home, especially flying a US carrier, since they tend to be more flexible if you miss a flight (compared to Asia, Europe, etc.).

Bottom line

Especially in the miles & points world, it’s common to see people book flights across multiple tickets. This is often necessary if redeeming miles for a long haul flight out of a gateway, and then needing to position.

It can be hard to decide on the right buffer. Obviously the bigger the buffer, the better the odds of everything going smoothly. At the same time, adding an overnight layover can add a lot of time and expense to a trip.

My general rule of thumb is that I try to leave a buffer of at least four hours between separate tickets, with at least one flight between the two that would still get me to that destination in time to make the flight. Admittedly there are many other considerations as well, so that’s not some hard and fast rule.

What approach do you take when it comes to leaving a buffer between separate itineraries?