When you create a Contact List and add numbers, a default country code is selected for each contact. However, you can always change a projects country code which will not affect other or future projects. This would essentially lock the given country to avoid constantly changing a phone number's country code for your contact.
Follow these steps to get started.
Step 1 — Go to your Project Settings
Click the Manage tab in the sidebar.
Step 2 — Select a different country
Click the current country to open a drop down menu, then select a new country.
Step 3 — Save your changes
After making your selection, click Save.