International calls are expensive under many phone plans. You may want to avoid allowing international phone service to save money, protect yourself against phone scams, avoid unwanted overseas calls or any number of other reasons. While it's not hard to set this up for outgoing calls, preventing incoming international calls is a trickier proposition.
How to Block Outgoing International Calls
Most phone services block outgoing international calls for both landline and mobile services upon request. To turn the feature on, you most likely will need to call your phone carrier and ask a customer service representative to activate it for you.
Some companies, like AT&T, offer a way to manage outgoing international service on your account online. Look for "Call Blocking" or "Outgoing Calls" in your account services. The process for blocking international calls generally is the same for both landlines and cellphones. However, these blocks do not affect outgoing calls to Canada or U.S. Territories like Puerto Rico, the Northern Marianas, and the U.S. Virgin Islands.
Blocking Incoming International Calls
Unfortunately, the world is a big place and few phone carriers are willing to block every country code and area code out there. There are some exceptions, or similar services that can be used to accomplish this goal. For example, Charter offers free international call blocking, and Cox offers a service called "Selective Call Acceptance" that allows you to block all calls except those from numbers you have approved. Check with your provider to see if they offer a similar service.
If your carrier does not offer blocking for all incoming international calls, you may be able to block unwanted incoming calls by adding specific numbers to your list of blocked callers. Dial *60 from a cellphone, or 1160 from a landline. Follow the recorded instructions and enter the number you wish to block. Some phone carriers limit the number of blocked callers you can enter; and some don’t provide a number field long enough to include country codes. Verizon, for instance, places restrictions that effectively eliminate the ability to block international calls using that approach.
However, some services, such as Sprint, will block international calls as long as they fit the 10-digit entry field. International phone numbers range from 7 to 16 digits, and the country code must be part of the number entered.
Although phone carriers usually don't offer a carte blanche solution for preventing incoming international calls, pay-for-service solutions offer to silence all calls from unrecognized numbers. Prices and specific services offered vary.