The longer answer says you need to be careful. Careful means watch how things are combined. The technique that you were looking at is called split ticketing, or sum of one ways. At future.travel our algorithms look for the cheapest fares including using split ticketing and sum of ways. OTA’s need to be very specific on what They present.
First do not use sum of one ways or split ticketing for one way ticketing. This is a disaster waiting to happen. When you’re combining multiple flights on a one-way trip there’s always a chance of a missed connection or late flight. The fact that the ticket is on multiple tickets adds more chance of unrelated airline failures. Unrelated airlines, as in two separate tickets, unrelated airlines, as in two separate do not support each other.
The same rule applies if it is a round trip ticket. You should not be changing airlines that are not on the same ticket going in one direction on a round trip ticket.
Split ticketing does work well on round-trip tickets where one direction is on one airline, and the return direction is on a different airline.
Why does it work well? Because statistically about 22% of the time two one way tickets are cheaper than a round trip ticket. When you have an OTA do the search for you they are wearing the risk of making sure they can get you the tickets. For the average shopper you have a problem if you buy one ticket only to find the second half is sold out. A good OTA will find you the best ticketing options and get you the seats, faster quicker and cheaper than you can do it yourself.
