Aer Lingus is the Republic of Ireland's national airline, with headquarters located at Dublin Airport. In addition to its main centre, it also has hubs in Cork and Belfast in Ireland. Aer Lingus was founded by the Irish government in 1936, but was later sold and privatised. It is listed on both the Dublin and the London Stock Exchanges. The airline's name comes from the Irish word for "air fleet". Aer Lingus uses all Airbus planes for its fleet, which stands at more than 40 aircraft. Airbus A320s make up the largest portion of the fleet, with the rest a mixture of A319s, A321s and A330s.

Among Aer Lingus' routes, some of the most popular are flights to Malaga in Spain, Venice in Italy and Pula in Croatia. It has codeshares with United Airlines, British Airways, Etihad Airways, KLM, JetBlue Airways, Air Canada and Flybe. Aer Lingus was once part of the Oneworld alliance, but currently has no organisational affiliations.

Online check-in

Check in can be done online for Aer Lingus flights beginning 30 hours before departure and closing 2 hours prior to takeoff. If passengers pay extra, they have the luxury of being able to choose their seat. Paying more so also allows them to check in up to 30 days ahead of their flight. If passengers choose not to pay to select their seat, it will be automatically assigned for them when they check in. Online check-in can be done either on a computer or on a mobile phone, with passengers needing their booking reference to do so. Aer Lingus passengers can also check in for their flight at the airport.

Hand luggage allowance

Hand luggage is limited to a maximum size of 55 x 40 x 24 cm, including any protrusions such as handles or wheels. Hand luggage on Aer Lingus is also subject to a weight maximum of 10 kg. Aer Lingus also specifies that passengers must be able to lift their own bags into the overhead storage compartment. If passengers exceed their weight or size allowance for hand luggage on an Aer Lingus flight, they will be charged a fee to check in their baggage instead. Passengers travelling with children may bring a foldable pram and a car seat without having to pay an extra charge.

Checked baggage policy

Checked baggage allowance on an Aer Lingus flight is determined by its destination. On flights within Europe, passengers can choose to pay for checked baggage either when booking or later online. The options available are for 1 bag of up to 15 kg, 20 kg or 25 kg, or 2 bags with a combined maximum weight of 40 kg. If passengers wish to take any sporting equipment they should go online to book it in advance. The maximum weight for sporting equipment is 23 kg, plus there is a limit of 1 item of sporting equipment per passenger. Aer Lingus charges a fee for baggage that exceeds any of these limitations.