Gay and lesbian couples began entering into civil partnerships in Ireland April 5.
The law took effect Jan. 1, but requires couples to give three months' notice prior to tying the knot before a registrar.
Civil partners receive marriage rights and obligations in matters such as taxes, pensions, property, tenancy, inheritance, alimony, immigration and social benefits.
To end a partnership, a couple must go before a court and prove they've not lived together for two of the last three years.
The law also recognizes foreign same-sex unions and provides some rights for unregistered couples who have lived together for at least five years.
Justice Minister Dermot Ahern called the law "one of the most important pieces of civil rights legislation to be enacted since independence."