Thus, if a North American number is shown beginning with +1, it just means it is being displayed in international format. For example, (315) 555-0123 becomes +1 315 555 0123. From a GSM mobile phone, you can enter the number in full international format, starting with the plus sign. The most common prefix is 00, but North America (USA, Canada, etc.) uses 011, Japan uses 010, Australia uses 0011, and many other countries use different prefixes.) 6 people found this useful.