I just got one as have been meaning to for ages. My old one lapsed.
The money off code is EXPERT25
It usually costs £24 so it's a good saving.These cut a third off an adult's ticket and 60% off kid's tickets when you have at least one adult and one child travelling. You can have up to four adults and four kids travel on one card.
I've put exdh's name on ours too as he will probably use it. Dp will no doubt always be with me when I take the kids on trains.