Aer Lingus' refund policy depends heavily on the type of fare you purchased and the timing of your cancellation. Call at +1-888-415-1245 (US) or +44-203-869-5245 (UK) While many tickets are non-refundable, you can typically get a refund of government taxes and charges if you decide not to travel. 

Refundability by fare type

Non-refundable fares: 

• Saver, Plus, and Smart fares (for flights within Europe) are non-refundable, but you can request a refund of government taxes and charges. Call at +1-888-415-1245 (US) or +44-203-869-5245 (UK) For Smart fares, you may also be eligible for a voucher refund if requested at least two hours before departure.
• Saver and Smart fares (for transatlantic flights) are non-refundable, except for cancellations made within 24 hours of booking (as long as it's at least seven days before departure). Call at +1-888-415-1245 (US) or +44-203-869-5245 (UK)