Aer Lingus online check-in and boarding pass: the traveller's guide

Aer Lingus online check-in opens several days before departure on most flights, and it's generally possible from at least the day before at the latest. This is the most common question travellers have ("how far in advance can I check in with Aer Lingus") and the answer depends on your route: a short-haul flight from Dublin and a transatlantic flight don't always open at the same point.

As for the closing time, give yourself plenty of margin. According to the airline's published information, online check-in generally closes several hours before takeoff, and airport counter check-in closes well ahead of the departure time. Aer Lingus's conditions of carriage actually define the "check-in deadline" as "the time limit specified by the airline for each flight for completing check-in formalities and receiving your boarding pass". In other words, the exact time is the one shown on your booking, and it isn't negotiable.

It's therefore best to check in as soon as the window opens: that's also when the widest choice of remaining free seats is available.

Three routes lead to the same Aer Lingus boarding pass:

Online check-in itself is free on Aer Lingus flights. What comes with a cost are the extras: advance seat selection, extra checked baggage, priority boarding. If you're asked to pay during the process, check the relevant line carefully before confirming.

Worth noting: some flights sold under the Aer Lingus Regional brand are operated by a partner and fall under its own conditions of carriage. The check-in process can then differ slightly.

Once check-in is confirmed, Aer Lingus makes the boarding pass available for download (PDF to print), in the mobile app, and usually by email to the address on the booking. The mobile format is accepted at security checkpoints in airports served by the airline, except for local exceptions flagged at the time of check-in: in that case, the site will ask you to print your pass or collect it on site.

If you're travelling as a family or group on the same booking, check that you have one pass per passenger. And if you have a connecting flight, check how many passes you received: a single pass covering two segments often means you'll need to go back to a counter at the layover.

Many searches are about checking in with Aer Lingus without a passport or with an ID card. The principle is simple: the documents required depend on the destination and your nationality, not on the check-in channel.

• Flights between countries in the European Economic Area and Switzerland: a valid national ID card is generally enough for EU or EEA citizens.
• Ireland and the United Kingdom: these countries are not part of the Schengen area and apply their own entry rules. Check before you leave whether your ID card is accepted for your nationality, otherwise bring your passport.
• Transatlantic flights: check the destination country's passport and travel authorisation requirements. This information is entered during online check-in, which is why it's worth having it to hand.

Article 13 of Aer Lingus's conditions of carriage covers travel documents, administrative formalities, customs and security. On certain destinations, a document check may be requested before boarding, even if you've already checked in online: in that case, go to the counter or verification point indicated.

Online check-in doesn't exempt you from bag drop if you're checking a suitcase. At Aer Lingus, cabin baggage and checked baggage allowances depend on the fare purchased: the dimensions, weight and number of pieces allowed are shown on your booking and displayed at the boarding gates.

A few practical pointers:

• Checked baggage is generally cheaper to buy online before the flight than at the airport.
• Baggage is dropped off at a dedicated "bag drop" counter, which also closes ahead of departure: check the deadline shown for your flight.
• At Paris-Charles de Gaulle, as at other French airports served by the airline, Aer Lingus works with a ground handling partner: the terminal and counter number can change, so rely on the screens on site.
• Items forbidden in the cabin (liquids over the allowed volume, sharp objects) must go in checked baggage.

Give yourself plenty of time at the terminal: on flights departing from busy airports, security queues often take longer than check-in itself.

Aer Lingus online check-in can be refused for reasons that aren't unusual:

• You're too early: the check-in window isn't open yet for your flight.
• You're too late: past the online deadline, only the airport counter can check you in.
• Your destination requires an in-person document or visa check.
• You're travelling with an infant on lap, a pet, special assistance or particular equipment: these bookings often need to go through the counter.
• Your ticket was bought through an agency or tour operator and the booking reference isn't recognised: use the six-character Aer Lingus booking reference instead of the agency's.
• The flight is operated by a codeshare partner: check-in happens on the website of the airline actually operating the flight.

If the error message persists and time is running short, contact Aer Lingus customer service or head to the counter with plenty of margin. Other European airlines follow similar logic: you'll find the details of their procedures in our guide on Aegean check-in. Finally, if you'd rather not keep an eye on the opening time yourself, iBoardingPass can carry out your check-in as soon as it opens and send you your boarding pass by email.