I don't know the answer, but why don’t you call the an post helpline, have found them very helpful with any queries i had.
For non spouses/partners, joint name state savings, are probably not a good idea, especially when it makes no difference when half the total invested in two seperate accounts amounts to the exact same thing.
I had one maturing a few years back, and caused issues, as the check is made out to both parties, so we couldn’t lodge it, until we opened a joint bank account.