Any error messages when you try to enter it?
Is it a valid address and eircode in the Republic of Ireland?
Addresses outside this country are not allowed.
Are you sure that you're entering it correctly - in particular the eircode?
I'm not sure if it requires the eircode with or without a space between the two parts of the eircode so try both.
If you need to contact 48 support about this then see the links in my signature below.
