Sim card not working after a return journey up belfast

[dalyer]

See here - the section titled "Returned Home?":

• https://community.48.ie/t5/The-Knowledge-Base/The-Roaming-Troubleshooting-Guide/ta-p/52179

If that doesn't help then you'll probably need to contact 48 support for further assistance. 

If you need to contact them then see the links in my signature below.