I bought a house in 2005 as an FTB.
I got married two years ago and we're thinking of buying a house together. My wife has never bought a house. If we purchase a house together, do we qualify as FTBs?
Because (for no good reason other than that is the 'way' they do it) @anb1170 is referring to a purchase whereby you buy as joint owners either as 'joint tenants' or 'tenants-in-common'.
What you do is your wife buys the property in her name solely. You will be on mortgage jointly so don't worry.
Then she will be a first time buyer for tax purposes - and indeed this scheme has the endorsement of Michael Noonan as he floated it on Pat Kenny some time ago.
There is your solution.
The question needs to be asked - why do Revenue do things like this?
[Here is another: You can get relief also for borrowings to repair your principal private residence where it is a rented premises. Do they tell you? Nah.]
I don't think any banks allow married people to buy PPRs other than in joint names.
I'm fairly sure there are no Revenue benefits to being a First Time Buyer any more so don't think it's going to make any difference to you. You may find banks targeting some of their products at FTBs, and they may consider you as one.