How to check in online with American Airlines

With American Airlines, online check-in opens 24 hours before departure, on aa.com or in the American Airlines app. It closes 90 minutes before an international flight, as a flight departing from the UK does, and that's earlier than the airport desks: in most cases, those remain open until 60 minutes before. To open the booking you need the passenger's last name, their date of birth and either the six-letter confirmation code or the ticket number.

Below we set out what to have to hand before you start, how the process runs on aa.com and in the app, where the boarding pass can go, and what's left to do once you're at the airport.

The window opens 24 hours before departure, as you'd expect. What's less usual is how early online check-in closes.

Closing is where American Airlines parts company with most airlines. On an international flight, and every departure from the UK is one, the online window shuts 90 minutes before, while the check-in desks and the bag drop stay open, in most cases, until 60 minutes before. That leaves half an hour in the middle when the phone is no longer an option but the desk still is. Within the United States, the two deadlines are the same: 45 minutes before departure.

A number of airports elsewhere close earlier still, most of them at 75 minutes, though no UK airport is on that list. American Airlines publishes it in full on its check-in page.

As for when to arrive, American Airlines recommends at least three hours for flights leaving from outside the United States, the UK among them, and two hours for flights within.

Before you start, have the following to hand:

• the passenger's last name;

• their date of birth, which American Airlines asks for as a security check;

• the confirmation code, six letters, or the ticket number, thirteen digits beginning 00115 or 0012.

The confirmation code is on the confirmation email and on the boarding pass, and the ticket number comes by email when the ticket is issued. Either one lets you access the booking, so a missing confirmation code isn't the end of it.

There's a second way in, which is to sign in to an AAdvantage account and pick the trip out of the list rather than typing anything.

Now that you have everything you need, we can go through the check-in itself.

How to check in online with American Airlines:

1. Go to Manage trips / Check-in on aa.com, or open the American Airlines app.

2. Enter the last name, the date of birth and the confirmation code or ticket number, then select Find your trip.

3. Work through the steps and confirm the details you're asked for.

4. Choose where you want the boarding pass: on your phone, in your phone's wallet, or printed.

The check-in process is the same on the website and in the app, and the main difference is how you receive your boarding pass. Both are set out below.

Once check-in is done, the boarding pass can go three ways: onto your phone, into your phone's wallet, or onto paper. Whichever you pick, the whole barcode has to be visible for it to be scanned.

Adding it to your phone's wallet also means you'll receive flight updates there.

At the airport

Self-service kiosks and curbside check-in are available at most airports, so if the online window has closed there's still more than one way to get a boarding pass.

The check-in desks and the bag drop close 60 minutes before an international flight, and 45 minutes before a flight within the United States. American Airlines recommends arriving at least three hours before an international departure.

On a flight operated by one of American Airlines partner airlines, none of these times apply: the airline flying the aircraft sets its own.

Not every airport takes a boarding pass on a phone

American Airlines accepts mobile boarding passes at most airports, but not all of them, and that includes airports where you change planes as well as the one you leave from.

There isn't a single list. Instead, American Airlines gives details for each airport, and whether mobile passes are accepted is shown there under Airport details. It's worth a look before you set off, because if the answer is no, the pass has to be on paper: printed at home, or from a self-service kiosk when you arrive.

You checked in in good time, you got to the gate when you were meant to, and your booking was confirmed. Even so, a delay, a cancellation or an overbooked flight can still get in the way of your plans.

If that happens and the airline is responsible, UK261 entitles you to compensation of up to £520 per passenger, depending on how far you were due to fly.

Which leg it covers depends on the direction. The flight out is covered, because it leaves a UK airport and the rules apply to every airline departing from one. The flight home is a different matter: American Airlines is neither a UK nor an EU airline, so a delay on the way back from Dallas, Miami or New York falls outside UK261, and outside the European rules as well.

If your American Airlines flight departs from an airport in the EU, the equivalent European rules apply instead, under Regulation EC 261/2004.

Being turned away at the gate is covered too: our guide to denied boarding sets out where you stand. And to see what you may be owed for your own flight, start with our American Airlines compensation page.

Keeping track of your American Airlines flight

With check-in out of the way, all that's left is the wait. It's well worth keeping an eye on your flight status in the meantime, particularly if you have a connection to make or someone meeting you at the other end.

American Airlines lets you check your flight status online without opening your booking, so you can see whether the departure time has changed or the flight has been delayed. If you've added your boarding pass to your phone's wallet, you can also receive flight updates there, making it easier to spot changes while you're on the move.

You could also use the free AirHelp app, which does one thing more: if your flight is delayed by more than 3 hours, is cancelled, or you're denied boarding, the app automatically checks whether you're entitled to compensation under UK261/EC 261 and lets you know.

With the AirHelp app you can:

• receive real-time notifications about delays, cancellations, gate changes and baggage reclaim;

• scan your boarding pass to add your flight quickly;

• share your flight status with whoever is picking you up;

• automatically check whether a disruption entitles you to compensation of up to £520;

• start your compensation claim straight from the app, with no paperwork.

The app is free and available on iOS and Android.