This is an attempted mapping of United States Postal Service Index of Countries and Localities (ICL) to two-letter ISO 3166-1 country codes and ISO 3166-2 country-subdivision code pairs. For instance, the ISO 3166-1 two-letter code for the United Kingdom is GB; the ISO 3166-2 code pairs for England and Wales are GB-ENG and GB-WLS, respectively.

The USPS requires (particularly when using their Web Tools API) to use ICL names for addressing. However, much general purpose software and services utilize the ISO standard (eg. FedEx).

This is not an authoritative listing. Use at your own risk. Feel free to e-mail upates to william@25thandClement.com. I do not own a copy of the ISO 3166-2:1998 standard.

Two principal resources for this compilation are the Wikipedia ISO pages and Statoids. Variations in regional names and spellings are cross-checked through a sampling of random web pages (that is to say, searching on Google for each spelling do you arrive at pages which describe the exact same place; UAE spellings, in particular, were done this way, despite that the names were obviously the same), unless the relevent Wikipedia entries specifically make note of the variations.

'Abu Dhabi (United Arab Emirates)'			=> 'AE-AZ',
'Admiralty Islands (Papua New Guinea)'			=> '',
'Afghanistan'						=> 'AF',
'Aitutaki (Cook Islands) (New Zealand)'			=> '',
'Ajman (United Arab Emirates)'				=> 'AE-AJ',
'Aland Island (Finland)'				=> '',
'Albania'						=> 'AL',
'Alderney, Channel Islands (Great Britain)'		=> '',
'Algeria'						=> 'DZ',
'Alhucemas (Spain)'					=> '',
'Alofi Island (New Caledonia)'				=> '',
'Andaman Islands (India)'				=> 'IN-AN',
'Andorra'						=> 'AD',
'Angola'						=> 'AO',
'Anguilla'						=> 'AI',
'Anjouan (Comoros)'					=> '',
'Annobon Island (Equatorial Guinea)'			=> '',
'Antigua and Barbuda'					=> 'AG',
'Argentina'						=> 'AR',
'Armenia'						=> 'AM',
'Aruba'							=> 'AW',
'Ascension'						=> '',
'Astypalaia (Greece)'					=> '',
/* Astypalaia is in Dodecanese prefecture, GR-81 */
'Atafu (Western Samoa)'					=> '',
'Atiu (Cook Islands) (New Zealand)'			=> '',
'Australia'						=> 'AU',
'Austria'						=> 'AT',
'Avarua (New Zealand)'					=> '',
'Azerbaijan'						=> 'AZ',
'Azores (Portugal)'					=> '',
'Bahamas'						=> 'BS',
'Bahrain'						=> 'BH',
'Balearic Islands (Spain)'				=> 'ES-PM',
'Baluchistan (Pakistan)'				=> '',
'Bangladesh'						=> 'BD',
'Banks Island (Vanuatu)'				=> '',
'Barbados'						=> 'BB',
'Barbuda (Antigua and Barbuda)'				=> '',
'Barthelemy (Guadeloupe)'				=> '',
'Belarus'						=> 'BY',
'Belgium'						=> 'BE',
'Belize'						=> 'BZ',
'Benin'							=> 'BJ',
'Bermuda'						=> 'BM',
'Bhutan'						=> 'BT',
'Bismark Archipelago (Papua New Guinea)'		=> '',
'Bolivia'						=> 'BO',
'Bonaire (Netherlands Antilles)'			=> '',
'Borabora (French Polynesia)'				=> '',
'Borneo (Kalimantan) (Indonesia)'			=> '',
/* Borneo is broken into 4 provinces: Barat (West), Selatan (South), Tengah (Central) and Timur (East) (ID-KB, ID-KS, ID-KT, ID-KI) */
'Borneo (North) (Malaysia)'				=> '',
/* Borneo is broken into 2 states: Sabah, Sarawak (MY-12, MY-13) */
'Bosnia-Herzegovina'					=> 'BA',
'Botswana'						=> 'BW',
'Bougainville (Papua New Guinea)'			=> '',
'Bourbon (Reunion)'					=> '',
'Brazil'						=> 'BR',
'British Guiana (Guyana)'				=> '',
'British Honduras (Belize)'				=> '',
'British Virgin Islands'				=> 'VG',
'Brunei Darussalam'					=> 'BN',
'Buka (Papua New Guinea)'				=> '',
'Bulgaria'						=> 'BG',
'Burkina Faso'						=> 'BF',
'Burma'							=> 'MM',
'Burundi'						=> 'BI',
'Caicos Islands (Turks and Caicos Islands)'		=> '',
'Cambodia'						=> 'KH',
'Cameroon'						=> 'CM',
'Canada'						=> 'CA',
'Canary Islands (Spain)'				=> 'ES-CN',
/* IC is reserved for Canary Islands */
'Canton Island (Kiribati)'				=> '',
'Cape Verde'						=> 'CV',
'Cayman Islands'					=> 'KY',
'Central African Rep.'					=> 'CF',
'Ceuta (Spain)'						=> 'ES-CE',
/* EA is reserved for Ceuta Melilla */
'Ceylon (Sri Lanka)'					=> '',
'Chad'							=> 'TD',
'Chaferinas Islands (Spain)'				=> '',
'Chalki (Greece)'					=> '',
/* Chalki is in the Dodecanese prefecture, GR-81 */
'Chile'							=> 'CL',
'China'							=> 'CN',
'Christmas Island (Australia)'				=> '',
'Christmas Island (Kiribati)'				=> '',
'Cocos Island (Australia)'				=> '',
'Colombia'						=> 'CO',
'Comoros'						=> 'KM',
'Congo, Democratic Republic of the'			=> 'CD',
'Congo, Republic of the (Brazzaville)'			=> 'CG',
'Cook Islands (New Zealand)'				=> 'CK',
'Corsica (France)'					=> '',
'Corisco Island (Equatorial Guinea)'			=> '',
'Costa Rica'						=> 'CR',
'Côte d'Ivoire'						=> 'CI',
'Crete (Greece)'					=> '',
/* Crete is broken into 4 prefectures: Chania, Rethimno, Heraklion and Lasithi (GR-??, GR-93, GR-91, GR-92) */
'Croatia'						=> 'HR',
'Cuba'							=> 'CU',
'Cumino Island (Malta)'					=> '',
'Curacao (Netherlands Antilles)'			=> '',
'Cyjrenaica (Libya)'					=> '',
'Cyprus'						=> 'CY',
'Czech Republic'					=> 'CZ',
'Dahomey (Benin)'					=> '',
'Damao (India)'						=> 'IN-DD',
'Danger Islands (New Zealand)'				=> '',
'Denmark'						=> 'DK',
'Desirade Island (Guadeloupe)'				=> '',
'Diu (India)'						=> 'IN-DD',
'Djibouti'						=> 'DJ',
'Dodecanese Islands (Greece)'				=> 'GR-81',
'Doha (Qatar)'						=> '',
'Dominica'						=> 'DM',
'Dominican Republic'					=> 'DO',
'Dubai (United Arab Emirates)'				=> 'AE-DU',
'East Timor (Indonesia)'				=> 'TL',
'Ecuador'						=> 'EC',
'Egypt'							=> 'EG',
'Eire (Ireland)'					=> '',
'El Salvador'						=> 'SV',
'Ellice Islands (Tuvalu)'				=> '',
'Elobey Islands (Equatorial Guinea)'			=> '',
'Enderbury Island (Kiribati)'				=> '',
'England (Great Britain and Northern Ireland)'		=> 'GB-ENG',
'Equatorial Guinea'					=> 'GQ',
'Eritrea'						=> 'ER',
'Estonia'						=> 'EE',
'Ethiopia'						=> 'ET',
'Fakaofo (Western Samoa)'				=> '',
'Falkland Islands'					=> 'FK',
'Fanning Island (Kiribati)'				=> '',
'Faroe Islands'						=> 'FO',
'Fernando Po (Equatorial Guinea)'			=> '',
'Fezzan (Libya)'					=> '',
'Fiji'							=> 'FJ',
'Finland'						=> 'FI',
'Formosa (Taiwan)'					=> 'TW',
'France'						=> 'FR',
'French Guiana'						=> 'GF',
'French Oceania (French Polynesia)'			=> '',
'French Polynesia'					=> 'PF',
'French Somaliland (Djibouti)'				=> '',
'French Territory of the Afars and Issas (Djibouti)'	=> '',
'French West Indies (Guadeloupe or Martinique)'		=> '',
'Friendly Islands (Tonga)'				=> '',
'Fujairah (United Arab Emirates)'			=> 'AE-FU',
'Futuna (Wallis and Futuna Islands)'			=> '',
'Gabon'							=> 'GA',
'Gambia'						=> 'GM',
'Gambier (French Polynesia)'				=> '',
'Georgia, Republic of'					=> 'GE',
'Germany'						=> 'DE',
'Ghana'							=> 'GH',
'Gibraltar'						=> 'GI',
'Gilbert Islands (Kiribati)'				=> '',
'Goa (India)'						=> 'IN-GA',
'Gozo Island (Malta)'					=> '',
'Grand Comoro (Comoros)'				=> '',
'Great Britain and Northern Ireland'			=> 'GB',
'Greece'						=> 'GR',
'Greenland'						=> 'GL',
'Grenada'						=> 'GD',
'Grenadines (St. Vincent and the Grenadines)'		=> '',
'Guadeloupe'						=> 'GP',
'Guatemala'						=> 'GT',
'Guernsey, Channel Islands (Great Britain)'		=> 'GB-GSY',
'Guinea'						=> 'GN',
'Guinea-Bissau'						=> 'GW',
'Guyana'						=> 'GY',
'Hainan Island (China)'					=> 'CN-46',
'Haiti'							=> 'HT',
'Hashemite Kingdom (Jordan)'				=> 'JO',
'Hervey (Cook Islands) (New Zealand)'			=> '',
'Hivaoa (French Polynesia)'				=> '',
'Holland (Netherlands)'					=> '',
/* Holland probably is synonymous with NL here, however NL contains two provinces: North Holland and South Holland (NL-NH, NL-ZH) */
'Honduras'						=> 'HN',
'Hong Kong'						=> 'HK',
'Huahine (French Polynesia)'				=> '',
'Huan Island (New Caledonia)'				=> '',
'Hungary'						=> 'HU',
'Iceland'						=> 'IS',
'India'							=> 'IN',
'Indonesia'						=> 'ID',
'Iran'							=> 'IR',
'Iraq'							=> 'IQ',
'Ireland'						=> 'IE',
'Irian Barat (Indonesia)'				=> 'ID-IJ',
'Isle of Man (Great Britain)'				=> 'GB-IOM',
'Isle of Pines (New Caledonia)'				=> '',
'Isle of Pines, West Indies (Cuba)'			=> '',
'Israel'						=> 'IL',
'Italy'							=> 'IT',
'Jamaica'						=> 'JM',
'Japan'							=> 'JP',
'Jersey (Channel Islands) (Great Britain)'		=> 'GB-JSY',
'Johore (Malaysia)'					=> 'MY-01',
'Jordan'						=> 'JO',
'Kalymnos (Greece)'					=> '',
/* Kalymnos is in the Dodecanese prefecture, GR-81 */
'Kampuchea (Cambodia)'					=> 'KH',
'Karpathos (Greece)'					=> '',
/* Karpathos is in the Dodecanese prefecture, GR-81 */
'Kassos (Greece)'					=> '',
/* Kassos is in the Dodecanese prefecture, GR-81 */
'Kastellorizon (Greece)'				=> '',
/* Kastellorizon is in the Dodecanese prefecture, GR-81 */
'Kazakhstan'						=> 'KZ',
'Kedah (Malaysia)'					=> 'MY-02',
'Keeling Islands (Australia)'				=> '',
'Kelantan (Malaysia)'					=> 'MY-03',
'Kenya'							=> 'KE',
'Kiribati'						=> 'KI',
'Korea, Republic of (South Korea)'			=> 'KR',
'Kos (Greece)'						=> '',
/* Kos is in the Dodecanese prefecture, GR-81 */
'Kowloon (Hong Kong)'					=> '',
'Kuwait'						=> 'KW',
'Kyrgyzstan'						=> 'KG',
'Labrador (Canada)'					=> 'CA-NL',
'Labuan (Malaysia)'					=> 'MY-15',
'Laos'							=> 'LA',
'Latvia'						=> 'LV',
'Lebanon'						=> 'LB',
'Leipsos (Greece)'					=> '',
/* Leipsos (Lipso) is in the Dodecanese prefecture, GR-81 */
'Leros (Greece)'					=> '',
/* Leros is in the Dodecanese prefecture, GR-81 */
'Les Saints Island (Guadeloupe)'			=> '',
'Lesotho'						=> 'LS',
'Liberia'						=> 'LR',
'Libya'							=> 'LY',
'Liechtenstein'						=> 'LI',
'Lithuania'						=> 'LT',
'Lord Howe Island (Australia)'				=> '',
'Loyalty Islands (New Caledonia)'			=> '',
'Luxembourg'						=> 'LU',
'Macao'							=> 'MO',
'Macau (Macao)'						=> 'MO',
'Macedonia'						=> 'MK',
'Madagascar'						=> 'MG',
'Madeira Islands (Portugal)'				=> '',
'Malacca (Malaysia)'					=> 'MY-04',
'Malagasy Republic (Madagascar)'			=> '',
'Malawi'						=> 'MW',
'Malaya (Malaysia)'					=> 'MY',
'Malaysia'						=> 'MY',
'Maldives'						=> 'MV',
'Mali'							=> 'ML',
'Malta'							=> 'MT',
'Manahiki (New Zealand)'				=> '',
'Manchuria (China)'					=> '',
/* Manchuria is broken into 3 provinces: Jilin, Heilongjiang, Liaoning (CN-22, CN-23, CN-21) */
'Mangaia (Cook Islands) (New Zealand)'			=> '',
'Manuai (Cook Islands) (New Zealand)'			=> '',
'Marie Galante (Guadeloupe)'				=> '',
'Marquesas Islands (French Polynesia)'			=> '',
'Martinique'						=> 'MQ',
'Mauke (Cook Islands) (New Zealand)'			=> '',
'Mauritania'						=> 'MR',
'Mauritius'						=> 'MU',
'Mayotte (France)'					=> 'YT',
'Melilla (Spain)'					=> 'ES-ML',
/* EA is reserved for Ceuta Melilla */
'Mexico'						=> 'MX',
'Miquelon (St. Pierre and Miquelon)'			=> '',
'Mitiaro (Cook Islands) (New Zealand)'			=> '',
'Moheli (Comoros)'					=> '',
'Moldova'						=> 'MD',
'Monaco (France)'					=> 'MC',
'Mongolia'						=> 'MN',
'Montserrat'						=> 'MS',
'Moorea (French Polynesia)'				=> '',
'Morocco'						=> 'MA',
'Mozambique'						=> 'MZ',
'Muscat (Oman)'						=> '',
'Myanmar (Burma)'					=> '',
'Namibia'						=> 'NA',
'Nansil Islands (Ryukyu Islands) (Japan)'		=> '',
'Nauru'							=> 'NR',
'Negri Sembilan (Malaysia)'				=> 'MY-05',
'Nepal'							=> 'NP',
'Netherlands'						=> 'NL',
'Netherlands Antilles'					=> 'AN',
'Netherlands West Indies (Netherlands Antilles)'	=> '',
'Nevis (St. Christopher and Nevis)'			=> 'KN',
'New Britain (Papua New Guinea)'			=> '',
'New Caledonia'						=> 'NC',
'New Hanover (Papua New Guinea)'			=> '',
'New Hebrides (Vanuatu)'				=> '',
'New Ireland (Papua New Guinea)'			=> '',
'New South Wales (Australia)'				=> 'AU-NS',
'New Zealand'						=> 'NZ',
'Newfoundland (Canada)'					=> 'CA-NL',
'Nicaragua'						=> 'NI',
'Niger'							=> 'NE',
'Nigeria'						=> 'NG',
'Nissiros (Greece)'					=> '',
/* Nissiros is in the Dodecanese prefecture, GR-81 */
'Niue (New Zealand)'					=> 'NU',
'Norfolk Island (Australia)'				=> 'NF',
'North Borneo (Malaysia)'				=> '',
'Norway'						=> 'NO',
'Nukahiva (French Polynesia)'				=> '',
'Nukunonu (Western Samoa)'				=> '',
'Nyasaland (Malawi)'					=> '',
'Ocean Island (Kiribati)'				=> '',
'Okinawa (Ryukyu Islands) (Japan)'			=> 'JP-47',
'Oman'							=> 'OM',
'Pahang (Malaysia)'					=> 'MY-06',
'Pakistan'						=> 'PK',
'Palmerston (Avarua) (New Zealand)'			=> '',
'Panama'						=> 'PA',
'Papua New Guinea'					=> 'PG',
'Paraguay'						=> 'PY',
'Parry (Cook Islands) (New Zealand)'			=> '',
'Patmos (Greece)'					=> '',
/* Patmos is in the Dodecanese prefecture, GR-81 */
'Pemba (Tanzania)'					=> '',
'Penang (Malaysia)'					=> 'MY-07',
'Penghu Islands (Taiwan)'				=> '',
'Penon de Velez de la Gomera (Spain)'			=> '',
'Penrhyn (Tongareva) (New Zealand)'			=> '',
'Perak (Malaysia)'					=> 'MY-08',
'Perlis (Malaysia)'					=> 'MY-09',
'Persia (Iran)'						=> 'IR',
'Peru'							=> 'PE',
'Pescadores Islands (Taiwan)'				=> '',
'Petite Terre (Guadeloupe)'				=> '',
'Philippines'						=> 'PH',
'Pitcairn Island'					=> 'PN',
'Poland'						=> 'PL',
'Portugal'						=> 'PT',
'Province Wellesley (Malaysia)'				=> '',
'Pukapuka (New Zealand)'				=> '',
'Qatar'							=> 'QA',
'Queensland (Australia)'				=> 'AU-QL',
'Quemoy (Taiwan)'					=> '',
'Raiatea (French Polynesia)'				=> '',
'Rakaanga (New Zealand)'				=> '',
'Rapa (French Polynesia)'				=> '',
'Rarotonga (Cook Islands) (New Zealand)'		=> '',
'Ras al Kaimah (United Arab Emirates)'			=> 'AE-RK',
'Redonda (Antigua and Barbuda)'				=> '',
'Reunion'						=> 'RE',
'Rhodesia (Zimbabwe)'					=> '',
'Rio Muni (Equatorial Guinea)'				=> '',
'Rodos (Greece)'					=> '',
/* Rodos (Rhodes) is in the Dodecanese prefecture, GR-81 */
'Rodrigues (Mauritius)'					=> '',
'Romania'						=> 'RO',
'Russia'						=> 'RU',
'Rwanda'						=> 'RW',
'Saba (Netherlands Antilles)'				=> '',
'Sabah (Malaysia)'					=> 'MY-12',
'Saint Bartholomew (Guadeloupe)'			=> '',
'Saint Christopher (St. Kitts) and Nevis'		=> 'KN',
'Saint Eustatius (Netherlands Antilles)'		=> '',
'Saint Helena'						=> 'SH',
'Saint Kitts (St. Christopher and Nevis)'		=> 'KN',
'Saint Lucia'						=> 'LC',
'Saint Maarten (Netherlands Antilles)'			=> '',
'Saint Martin (Guadeloupe)'				=> '',
'Saint Pierre and Miquelon'				=> 'PM',
'Saint Vincent and the Grenadines'			=> 'VC',
'Salvador (El Salvador)'				=> 'SV',
'San Marino'						=> 'SM',
'Santa Cruz Islands (Solomon Island)'			=> '',
'Sao Tome and Principe'					=> 'ST',
'Sarawak (Malaysia)'					=> 'MY-13',
'Sark, Channel Islands (Great Britain)'			=> '',
'Saudi Arabia'						=> 'SA',
'Savage Island (Niue) (New Zealand)'			=> '',
'Savaii Island (British) (Western Samoa)'		=> '',
'Scotland (Great Britain and Northern Ireland)'		=> 'GB-SCT',
'Selangor (Malaysia)'					=> 'MY-10',
'Senegal'						=> 'SN',
'Serbia-Montenegro'					=> 'CS',
'Seychelles'						=> 'SC',
'Sharja (United Arab Emirates)'				=> 'AE-SH',
'Shikoku (Japan)'					=> '',
'Siam (Thailand)'					=> '',
'Sierra Leone'						=> 'SL',
'Sikkim (India)'					=> 'IN-SK',
'Singapore'						=> 'SG',
'Slovak Republic'					=> 'SK',
'Slovenia'						=> 'SI',
'Society Islands (French Polynesia)'			=> '',
'Solomon Islands'					=> 'SB',
'Somali Democratic Republic (Somalia)'			=> 'SO',
'Somalia'						=> 'SO',
'Somaliland (Somalia)'					=> 'SO',
'South Africa'						=> 'ZA',
'South Australia (Australia)'				=> 'AU-SA',
'South Georgia (Falkland Islands)'			=> 'GS',
'South Korea (Korea, Republic of)'			=> 'KR',
'South-West Africa (Namibia)'				=> '',
'Spain'							=> 'ES',
'Spitzbergen (Norway)'					=> '',
'Sri Lanka'						=> 'LK',
'Ste. Marie de Madagascar (Madagascar)'			=> '',
'Sudan'							=> 'SD',
'Suriname'						=> 'SR',
'Suwarrow Islands (New Zealand)'			=> '',
'Swan Islands (Honduras)'				=> '',
'Swaziland'						=> 'SZ',
'Sweden'						=> 'SE',
'Switzerland'						=> 'CH',
'Symi (Greece)'						=> '',
/* Symi is in the Dodecanese prefecture, GR-81 */
'Syrian Arab Republic'					=> 'SY',
'Tahaa (French Polynesia)'				=> '',
'Tahiti (French Polynesia)'				=> '',
'Taiwan'						=> 'TW',
'Tajikistan'						=> 'TJ',
'Tanzania'						=> 'TZ',
'Tasmania (Australia)'					=> 'AU-TS',
'Tchad (Chad)'						=> '',
'Thailand'						=> 'TH',
'Thursday Island (Australia)'				=> '',
'Tibet (China)'						=> 'CN-54',
'Tilos (Greece)'					=> '',
/* Tilos is in the Dodecanese prefecture, GR-81 */
'Timor (Indonesia)'					=> 'ID-NT',
/* Nusa Tenggara Timur (Indonesian/West Timor, always administratively separate from Portugese/East Timor) */
'Tobago (Trinidad and Tobago)'				=> 'TT',
'Togo'							=> 'TG',
'Tokelau (Union) Group (Western Samoa)'			=> 'TK',
'Tonga'							=> 'TO',
'Tongareva (New Zealand)'				=> '',
'Tori Shima (Ryukyu Islands) (Japan)'			=> '',
'Torres Island (Vanuatu)'				=> '',
'Trans-Jordan (Hashemite Kingdom) (Jordan)'		=> 'JO',
'Transkei (South Africa)'				=> '',
'Trengganu (Malaysia)'					=> 'MY-11',
'Trinidad and Tobago'					=> 'TT',
'Tripolitania (Libya)'					=> '',
'Tristan da Cunha'					=> '',
'Trucial States (United Arab Emirates)'			=> 'AE',
'Tuamotou (French Polynesia)'				=> '',
'Tubuai (French Polynesia)'				=> '',
'Tunisia'						=> 'TN',
'Turkey'						=> 'TR',
'Turkmenistan'						=> 'TM',
'Turks and Caicos Islands'				=> 'TC',
'Tuvalu'						=> 'TV',
'Uganda'						=> 'UG',
'Umm Said (Qatar)'					=> '',
'Umm al Quaiwain (United Arab Emirates)'		=> 'AE-UQ',
'Ukraine'						=> 'UA',
'Union Group (Western Samoa)'				=> '',
'United Arab Emirates'					=> 'AE',
'Upolu Island (Western Samoa)'				=> '',
'Uruguay'						=> 'UY',
'Uzbekistan'						=> 'UZ',
'Vanuatu'						=> 'VU',
'Vatican City'						=> 'VA',
'Venezuela'						=> 'VE',
'Victoria (Australia)'					=> 'AU-VI',
'Vietnam'						=> 'VN',
'Wales (Great Britain and Northern Ireland)'		=> 'GB-WLS',
'Wallis and Futuna Islands'				=> 'WF',
'Wellesley, Province (Malaysia)'			=> '',
/* Province Wellesley is part of the state of Pulau Pinang, MY-07 */
'West New Guinea (Indonesia)'				=> '',
'Western Australia (Australia)'				=> 'AU-WA',
'Western Samoa'						=> '',
'Yemen'							=> 'YE',
'Zafarani Islands (Spain)'				=> '',
'Zambia'						=> 'ZM',
'Zanzibar (Tanzania)'					=> '',
'Zimbabwe'						=> 'ZW'