As I understand the answer is YES, but the policy varies by airline. You can always change the bookings for a €25 fee with Aer Lingus, which may be more cost effective depending on the original price. (i.e. Use them for a different trip)
What annoys me is that the fare is almost nothing, but you pay airport charges, taxes, booking fees, insurance surchares, fuel surcharges, etc. - but when you cancel only the taxes are refunded. Rip Off or what?