Amazon places shipping restrictions based on item and locale. The sale of items must obey the rules and regulations of the host country. It is possible, for example, that a host country would restrict the sale of some electronic equipment to specific countries. Some locales restrict shipping to specified countries regardless of the item. For example, in the UK locale, shipping is restricted to Ireland, Scotland, and England.
Because Amazon is used to fulfill the orders, Amazon takes charge of restricting shipping. Your application or website, however, should be aware of the shipping restrictions.
Shipping costs also play an important role in helping your customers purchase items for the lowest possible price. For example, Harry Potter books are available in all locales. A customer in the US could purchase a copy of a Harry Potter book from the UK locale. The shipping charges, however, would be significantly higher than if the same item were purchased through the US locale.
To see the latest details on shipping restrictions for each locale, see About Shipping Restrictions.