where do you see them offering 2.5%? As per their website the closest to a demand deposit i can see is their SIGNATURE DEPOSIT on call variable ac -which has a rate of 1.25% Gross
www[dot]permanenttsb[dot]ie/media/permanenttsb/pdfdocuments/depositrates/permanent-tsb-Deposit-Interest-Rates.pdf
See here: http://www.askaboutmoney.com/showthread.php?t=102329
and see here: [broken link removed]
The PTSB online account pays 2.5%. The PTSB accounts for 0-19 year olds pay 3.0%.