Why will Aer Lingus not let me check in online?

There are several reasons why Aer Lingus might not allow you to check in online, and most of them are related to either your booking details or specific travel requirements. Online check-in with Aer Lingus usually opens 48 hours before the scheduled departure time for most short-haul flights and 24 hours before for long-haul international flights. However, if you're unable to complete online check-in, it could be due to one or more of the following reasons.

One common reason is that your booking includes special services. For example, if you’ve requested assistance for reduced mobility, are traveling with a pet, or have special meal or medical needs, you might need to check in at the airport. This allows Aer Lingus staff to confirm details in person and provide the right support.

Another possibility is that you are traveling with an infant or child, especially if the child is not occupying a separate seat. In these cases, the system may require a manual check-in at the airport to ensure that seating and safety arrangements are properly made.

If your flight is operated by a partner airline or is part of a codeshare agreement, online check-in might be restricted. In such situations, passengers often need to check in through the partner airline’s website or directly at the airport.

Also, issues with travel documents can prevent online check-in. If your passport details are incomplete, expired, or incorrect, or if you need a visa verification for your destination, the airline might block online check-in and ask you to complete it at the airport instead.

Technical errors or glitches with the website or app can sometimes also interfere with online check-in, though these are less common. It's a good idea to try a different device or browser, or wait a little while and try again.

Finally, if your booking was made through a third-party travel agency, sometimes the booking information may not sync properly with the airline’s online system, which can also lead to check-in issues.

In summary, if Aer Lingus doesn’t let you check in online, it's usually for your safety, document verification, or because your situation requires personal assistance. In such cases, arriving early at the airport is important to ensure a smooth check-in process.