Addressing mail to the United Kingdom can be confusing. After researching the topic, we have found some issues. This document will describe the issues and our solutions.
To properly understand the problem, you must understand all the players.
• ENGLAND is one of the countries of Britain.
• SCOTLAND is one of the countries of Britain.
• WALES is one of the countries of Britain.
• NORTHERN IRELAND is a jurisdiction having approximately the same status as England, Scotland, and Wales, but on a different island.
The UNITED KINGDOM is the union of England, Scotland, Wales, and Northern Ireland, including whatever islands are also included in those countries. The full name of the United Kingdom is THE UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND. The United Kingdom itself is a country. Thus it is a country that is made up of four countries. A country made of countries might seem a paradox, yet the countries that make up the UK, especially England, Scotland, and Wales, do not think of themselves as anything less; Scotland has its own Parliament and banknotes, Wales has its own language and National Assembly, all three have national identities going back more than a thousand years, and the Encyclopedia Britannica calls them countries (next item). Perhaps more to the point, ENGLAND, SCOTLAND, WALES, and NORTHERN IRELAND are listed in the USPS Index of Countries and Localities. (According to the Oxford English Dictionary, the term UNITED KINGDOM was first used in 1801 and, until 1921, included Ireland.)
(taken from http://www.columbia.edu/kermit/l1-postal.html#uk)
The USPS prefers that all mail to England, Scotland, or Wales be addressed with GREAT BRITAIN. Northern Ireland should be addressed as NORTHERN IRELAND. (The United States Postal Service has computer systems that use UK as an abbreviation for "Ukraine".)
Receiving Addresses from eBay
Currently, whenever a buyer in any of the four UK countries purchases an item from you, eBay returns United Kingdom as the buyers country.
Technically eBay is simply returning the buyer's country, and UK is therefore correct. The problem arises because of the "country in a country" paradox. The different countries within the UK require different addressing, but eBay returns only one country code for all 4 countries. Therefore, SixBit can not tell which of the 4 UK countries the buyer is from.
Although eBay returns UNITED KINGDOM whenever the buyer is in any of the 4 previously mentioned countries, we have chosen not to save UNITED KINGDOM. Since this is not the preferred mailing address of any of the 4 countries, it would likely be rejected by the USPS and may cause issues.
Instead, we store GREAT BRITAIN as the text for any of the UK countries. This will provide accurate country identification on shipping labels to England, Scotland, and Wales. However, it will not provide the preferred addressing to Northern Ireland.
In addition, we have added "Northern Ireland" as a country that you can specify. eBay will never return this country, but if you happen to know it, you can select it.
Since there currently is no way to tell if a buyer is from Northern Ireland, there really is no other way to do it.