As of February 25, 2026, the rules have changed significantly: you can no longer fly with Aer Lingus to England without a passport. While the Common Travel Area (CTA) agreement between Ireland and the UK technically allows for passport-free travel on paper for British and Irish citizens, Aer Lingus has officially aligned its policy with Ryanair to require a valid passport or Irish Passport Card for all flights between the Republic of Ireland and Great Britain. This move was made to ensure "operational consistency" and to comply with the UK's fully enforced Electronic Travel Authorisation (ETA) system. Previously, passengers could use a driving license or other photo ID, but those are no longer accepted at the boarding gate for international routes. Only domestic flights within Ireland (e.g., Dublin to Donegal) or flights within the UK (e.g., Belfast to London) may still allow alternative IDs. If you are traveling between Dublin and London, you must have a passport to board an Aer Lingus aircraft.