The following are the only countries that use E26: USA, Canada, South America (except Brazil), Japan and Taiwan. The rest of the world uses E27.

Here's a list of every country and their Bulb type, if you'd like to know exact details:

  • Afghanistan 27
  • Aland Islands 27
  • Albania 27
  • Algeria 27
  • Andorra 27
  • Angola 27
  • Anguilla 26
  • Antigua And Barbuda 27
  • Argentina 27
  • Armenia 27
  • Aruba 26
  • Australia 27
  • Austria 27
  • Azerbaijan 27
  • Bahamas 26
  • Bahrain 27
  • Bangladesh 27
  • Barbados 26
  • Belarus 27
  • Belgium 27
  • Belize 26
  • Benin 27
  • Bermuda 26
  • Bhutan 27
  • Bolivia 27
  • Bosnia And Herzegovina 27
  • Botswana 27
  • Bouvet Island 27
  • Brazil 27
  • British Indian Ocean Territory 27
  • Brunei 27
  • Bulgaria 27
  • Burkina Faso 27
  • Burma 27
  • Burundi 27
  • Cambodia 27
  • Cameroon 27
  • Canada 26
  • Cape Verde 27
  • Cayman Islands 26
  • Central African Republic 27
  • Chad 27
  • Chile 27
  • China 27
  • Christmas Island 27
  • Cocos (Keeling) Islands 27
  • Colombia 26
  • Comoros 27
  • Congo 27
  • Congo, The Democratic Republic Of The 27
  • Cook Islands 27
  • Costa Rica 26
  • Croatia 27
  • Cuba 26
  • Cyprus 27
  • Czech Republic 27
  • Côte d'Ivoire 27
  • Denmark 27
  • Djibouti 27
  • Dominica 27
  • Dominican Republic 26
  • Ecuador 26
  • Egypt 27
  • El Salvador 26
  • Equatorial Guinea 27
  • Eritrea 27
  • Estonia 27
  • Ethiopia 27
  • Falkland Islands (Malvinas) 27
  • Faroe Islands 27
  • Fiji 27
  • Finland 27
  • France 27
  • French Guiana 27
  • French Polynesia 27
  • French Southern Territories 27
  • Gabon 27
  • Gambia 27
  • Georgia 27
  • Germany 27
  • Ghana 27
  • Gibraltar 27
  • Greece 27
  • Greenland 27
  • Grenada 27
  • Guadeloupe 27
  • Guatemala 26
  • Guernsey 27
  • Guinea 27
  • Guinea Bissau 27
  • Guyana 27
  • Haiti 26
  • Heard Island And Mcdonald Islands 27
  • Holy See (Vatican City State) 27
  • Honduras 26
  • Hong Kong 27
  • Hungary 27
  • Iceland 27
  • India 27
  • Indonesia 27
  • Iran, Islamic Republic Of 27
  • Iraq 27
  • Ireland 27
  • Isle Of Man 27
  • Israel 27
  • Italy 27
  • Jamaica 26
  • Japan 26
  • Jersey 27
  • Jordan 27
  • Kazakhstan 27
  • Kenya 27
  • Kiribati 27
  • Korea, Democratic People's Republic Of 27
  • Kosovo 27
  • Kuwait 27
  • Kyrgyzstan 27
  • Lao People's Democratic Republic 27
  • Latvia 27
  • Lebanon 27
  • Lesotho 27
  • Liberia 27
  • Libyan Arab Jamahiriya 26
  • Liechtenstein 27
  • Lithuania 27
  • Luxembourg 27
  • Macao 27
  • Macedonia, The Former Yugoslav Republic Of 27
  • Madagascar 27
  • Malawi 27
  • Malaysia 27
  • Maldives 27
  • Mali 27
  • Malta 27
  • Martinique 27
  • Mauritania 27
  • Mauritius 27
  • Mayotte 27
  • Mexico 26
  • Moldova, Republic of 27
  • Monaco 27
  • Mongolia 27
  • Montenegro 27
  • Montserrat 27
  • Morocco 27
  • Mozambique 27
  • Myanmar 27
  • Namibia 27
  • Nauru 27
  • Nepal 27
  • Netherlands 27
  • Netherlands Antilles 27
  • New Caledonia 27
  • New Zealand 27
  • Nicaragua 26
  • Niger 27
  • Nigeria 27
  • Niue 27
  • Norfolk Island 27
  • Norway 27
  • Oman 27
  • Pakistan 27
  • Palestinian Territory, Occupied 27
  • Panama 26
  • Papua New Guinea 27
  • Paraguay 27
  • Peru 27
  • Philippines 27
  • Pitcairn 27
  • Poland 27
  • Portugal 27
  • Qatar 27
  • Reunion 27
  • Romania 27
  • Russia 27
  • Rwanda 27
  • Saint Barthélemy 27
  • Saint Helena 27
  • Saint Kitts And Nevis 27
  • Saint Lucia 27
  • Saint Martin 27
  • Saint Pierre And Miquelon 27
  • Samoa 27
  • San Marino 27
  • Sao Tome And Principe 27
  • Saudi Arabia 27
  • Senegal 27
  • Serbia 27
  • Seychelles 27
  • Sierra Leone 27
  • Singapore 27
  • Slovakia 27
  • Slovenia 27
  • Solomon Islands 27
  • Somalia 27
  • South Africa 27
  • South Georgia And The South Sandwich Islands 27
  • South Korea 27
  • Spain 27
  • Sri Lanka 27
  • St. Vincent 27
  • Sudan 27
  • Suriname 27
  • Svalbard And Jan Mayen 27
  • Swaziland 27
  • Sweden 27
  • Switzerland 27
  • Syria 27
  • Taiwan 26
  • Tajikistan 27
  • Tanzania, United Republic Of 27
  • Thailand 27
  • Timor Leste 27
  • Togo 27
  • Tokelau 27
  • Tonga 27
  • Trinidad and Tobago 26
  • Tunisia 27
  • Turkey 27
  • Turkmenistan 27
  • Turks And Caicos Islands 27
  • Tuvalu 27
  • Uganda 27
  • Ukraine 27
  • United Arab Emirates 27
  • United Kingdom 27
  • United States 27
  • United States Minor Outlying Islands 27
  • Uruguay 27
  • Uzbekistan 27
  • Vanuatu 27
  • Venezuela 26
  • Vietnam 27
  • Virgin Islands, British 26
  • Wallis And Futuna 27
  • Western Sahara 27
  • Yemen 27
  • Zambia 27
  • Zimbabwe 27