The utility of O2 Call Barring spans several demographics. For parents, the ability to "bar all outgoing international calls" on a child’s phone prevents bill shock from premium-rate or long-distance dialing. For business travelers, "bar incoming when roaming" is a strategic financial tool; since many networks charge for receiving calls abroad, activating this barring ensures the user only pays for outgoing calls or data, not for unwanted marketing calls from home.

Enter your . The default code for O2 is usually 0000 . Method 2: Using Network Dial Codes

If you are an O2 Business customer, you can manage bars for multiple lines through the portal: