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Since it is often encouraged by airlines, I have adopted the habit of checking in online for flights, even if I am planning on taking suitcases with me.
How does this benefit me? If travelling with hand luggage only, one can often skip the check-in counters and proceed directly to security (an obvious timesaver), so let us assume that I will check bags.
- I have seen very few airports with dedicated bag drop counters for the passengers who have already checked in at home, so I will have to queue just like those who didn't make use of online check-in. (However at the airports I've been at with such counters, the amount of time saved has been significant, sometimes with nobody waiting at the bag drop counter and dozens at the regular check-in counter.)
- Unless travelling on an ultra low cost carrier, airport check-in does not cost more.
How does it benefit the airline? There must be a reason they always send those reminder e-mails 24h before departure?
- I don't think they are saving a lot of money on employees, since they still have to man the bag drop counters.
- Agents usually reprint my boarding pass without asking if I actually need one (I don't because I already have it), so printing costs are not reduced either.
- If everyone checked in at the airport and a passenger was delayed for boarding, it would be easier to decide if they should be waited for because they are already at the airport (i. e. checked in) or if the flight should just leave because they didn't even make it to the airport yet (i. e. not checked in).