Best answer by Mohammed
Welcome to our iD Community!
Calls & Texts to both Mobiles/Landlines are not included to the Channel Islands (Guernsey/Jersey) from the UK.
However, Guernsey & Jersey are both included as part of our inclusive EU Roaming destinations so if you're in one of those destinations, then calling or texting both UK numbers and Guernsey/Jersey would be included within your allowances. Using data in those destinations is also included.
Hope that answers your question!