Do you know if it's possible to block a landline no from ringing a mobile. Our bills are really astronomical and we have discovered its because our four older teenagers are using house phone to ring mobiles and staying on for hours. Going on hols next week for over 3 weeks, two older will be at home so they can go to town with the phone.
When speaking to your phone provider, ask for a block on international calls as well. The block on mobiles will only block the mobile prefixes (086, 087, etc), however it doesn't stop mobiles being rung as international numbers (using the international code for Ireland).
The block on international calls should stop this workaround!
Friend of mine found out about the workaround the hard way - when he got his phone bill, having set up mobile phone blocking!