1st, 2nd and 3rd Year in Ireland are equivalent to 1º, 2º and 3º de la ESO. Validation for any of these years in Spain would be automatic.
Nevertheless some schools in Spain might ask for an official translation of the results certificate obtained in Ireland. For this case a translation service is offered.
Transition Year, 5th and 6th Year are equivalent to 4º de la ESO, 1º and 2º de Bachillerato.
For validation in Spain of any of these school years you would need to follow the procedure established by the Spanish Education Ministry.
See table of equivalences >