ASINs were once unique worldwide, but global marketing has changed so that ASINs are only guaranteed unique within particular marketplaces. Accordingly, the same product may have several ASINs though, and different national sites may use a different ASIN for the same product. In general, ASINs are unlikely to be different between the country sites specially if they are for a class of product where the ASIN is based on an externally defined and internationally consistent identifier, such as ISBN for books.
Each product sold on Amazon.com is given a unique ASIN. For books with 10-digit International Standard Book Number (ISBN), the ASIN and the ISBN are the same. The Kindle edition of a book will not use its ISBN as the ASIN, although the electronic version of a book may have its own ISBN. In most cases, it is possible to convert an ASIN to obtain a corresponding EAN code, also known as an International Article Number.