Why not check online 'here' to see if you are.
If you are not on the Register of Electors in your local County Council, then you can download the (RFA2) registration form 'HERE'. Then simply follow the instructions on the form and take it to the Garda Station to have your identification verified. Then send it onto you local County Council office (Details below) and you will be placed on the Supplementary Register.
Remember, you must register with yout local County Council office up to 14 days before polling day in order to be included on the Supplementary Register.
Sligo County Council: Contact, Corporate Services Section, Sligo County Council, County Hall, Riverside, Sligo – Telephone: 071 9111012 or E-Mail: email@example.com
Leitrim County Council: Contact, Leitrim County Council, Áras An Chontae, Carrick on Shannon, Co. Leitrim - Telephone 071 9620005 or E-mail: firstname.lastname@example.org
Donegal County Council: Contact, Franchise Unit, Donegal County Council, County House Lifford, Co. Donegal - Telephone: 074 9172238 or E-Mail: email@example.com
Cavan County Council: Contact, Register of Electors, Freepost, Cavan County Council, The Courthouse, Cavan Town - Telephone: 049-4378600 or E-mail: firstname.lastname@example.org