If your PrestaShop store is viewable in many countries, it may be important for you to limit sales to those countries where you can ship.  Fortunately, PrestaShop does have this as a setting in the Localization menu for countries.  The following tutorial shows you how to quickly set the option to restrict your country selections that your customer can see to those that are covered by your active carriers.

Limiting the Country List in the Storefront per Shipping Zones in PrestaShop 1.5

1. Log in to the PrestaShop Admin Dashboard as an Administrator
2. Hover over the menu bar where it is labeled LOCALIZATION.  Click on COUNTRIES when it appears.  If you need to edit information for a country, go to Defining Countries in Prestashop 1.5 for further details. Scroll down to the bottom of the COUNTRIES screen and you will see the following:
   
   
   
   
   
   
3. Select the radial button to determine if you are restricting the country selections to those covered by the active carriers/shippers in your store. 
4. Click on SAVE in the top right hand corner of this section of the screen to save your selection.
   
   

Remember that your products can only get to your customers if it is shipped through a supported carrier or if they come to you and obtain their purchase directly.  If you are allowing shipping to a country in which you do not have support for a carrier, you will need to make separate arrangements directly with the customer in order to get your products shipped.  This may be something you need to consider based on your customer base and the products that you are selling.