Are you on Verizon Wireless and are having a problem with making Wi-Fi calls? In other words, you’re getting this: “Welcome to Verizon Wireless. Sorry, the number you dialed does not accept calls over Wi-Fi or from certain devices?”
Here is the simple solution to fix it. Make sure that all the contacts in your phone have the area code prefix included, so that all your phone numbers are 10-digit and your problem is solved.