FTP will be able to book seats online without getting charged the seat reserved fee.
Free Travel Bookings
20 July 2020
We are amending our online system to allow free travel pass and valid ticket holders to book onto trains towards the end of July. This option whilst shown is not yet active.
Iarnród Éireann Irish Rail apologise for any inconvenience caused.
It might be because its not fully ready but there does appear certain peak services excluded from reserving a seat and/or a limit on the number of "free" seats that can be reserved just like fare brackets are limited.
Obviously they can still travel but not guarnteed a seat.