Traveling from the UK to Ireland with Ryanair using only a UK driving licence is technically possible but highly risky due to conflicting policies. Under the Common Travel Area (CTA) agreement, British and Irish citizens do not strictly need a passport to travel between the two countries. However, Ryanair's own corporate policy is much stricter than government law: they generally require a valid passport or a National ID card for all international flights, including those between the UK and Ireland. While some ground staff might occasionally accept a driving licence for a domestic-ish CTA flight, Ryanair's terms and conditions explicitly state that a driving licence is not a valid form of ID for their international flights. If you attempt to board with only a driving licence, you run a high risk of being denied boarding at the gate. For a stress-free journey in 2026, you should always use a valid passport. If you do not have one, you should consider traveling by ferry (Stena Line or Irish Ferries), as they officially accept a UK driving licence with a photo as valid ID for British and Irish citizens crossing the Irish Sea within the Common Travel Area.