Just a friendly reminder that, despite the Common Travel Area allowing UK and Irish nationals to travel between the two countries without being required by law to show a passport, Ryanair has always required a passport (or "passport cards" which have been issued by Ireland only since 2015), for IE and UK citizens travelling between the two countries. In contrast, Aer Lingus will accept a much longer list of ID for CTA routes, including work and bus passes bearing a photo, student ID, and drivers licences.

As such, Ryanair has a long-standing history of imposing a much higher identification requirement than the underlying immigration law would require.

Someone upthread mentioned "tilting at windmills". You really aren't likely to get Ryanair to change on this point - they never budged on the issue for travel between UK and IE.

Remember also that the Home Office hasn't guaranteed that this particular exemption from the passport requirement will be extended beyond 2025, so Ryanair are probably correct in assuming that the requirement for a passport in law will soon match their current implementation.