If you request encashment online rather than by post then it should only take a few days for the money to be paid to the receiving account in my experience and according to this:
I've cashed in using online account. Money transferred to my bank account within days. Make sure you destroy original bond once cash hits your bank account in order to avoid possible confusion in years to come.
Quickly once some form from post office obtained... best enquire there. Maybe some ID needed? or was it some registration number from State Savings site?
Prize Bonds can be cashed in at any time after an initial holding period of 90 days and transferred to your Bank Account.
Simply complete a repayment form available here or at any Post Office and send it with:
1) the Prize Bond certificate* AND
2) a copy of a bank statement verifying the account name(s) and IBAN to:
Ireland State Savings, Prize Bonds, Fexco Centre, Killorglin, FREEPOST, Co. Kerry, V93 WN9T.