Hi, 
Eircodes are a grey area as for them to be included in OpenStreetMap. Eircodes pulled directly from their website cannot be used for insertion into OSM. Would have to have sources of whether they display it on a website/displayed on a sign on the shop etc for it to be acceptable, but even then it's still a rather iffy subject as to whether it can still be included.

I'll close this note but if you do manage to find a picture of it or linked somewhere, then that can be added as the source. 