Many U.S. treaty partners require the IRS to certify that the company claiming treaty benefits is a resident of the United States for the federal tax purposes. The IRS provides this residency certification on Form 6166, a letter of U.S. residency certification.
Form 6166 is a letter printed on U.S. Department of Treasury stationary certifying that the company was/is a resident of the United States for purposes of income tax laws of the United States. You may use this form to claim income tax treaty benefits and certain other tax benefits in foreign countries.
Form 6166 also sets forth the Employer Identification Number (EIN) of the company, and the tax year the letter is issue for.
If the document is intended for use in a foreign country it has to be legalized ("authenticated") for foreign use. This is a process in which various seals are placed on the document. If the target country has joined the Convention Abolishing the Requirement of Legalization for Foreign Public Documents ("The Hague Convention") the only legalization required is an Apostille. A document bearing an Apostille is valid in all of the Hague countries.
If the document is intended for a non-Hague country the consular legalization will be required. Before the consulate or the embassy can stamp the document, the document has to be authenticated on the state and federal levels.
Only certified copies as described above are accepted for further legalization. Computer generated or notarized copies cannot be accepted for legalization.
Form 6166 is a federal document therefore it is legalized on a federal level. Only original document can be accepted for legalization. Notarized copies are not accepted.FBI Background Checks
Countries (legalization): Afghanistan, Albania, Algeria, American Samoa, Andorra, Angola, Anguilla, Antigua and Barbuda, Argentina, Armenia, Aruba, Australia, Austria, Azerbaijan, Bahamas The, Bahrain, Bangladesh, Barbados, Belarus, Belgium, Belize, Benin, Bermuda, Bolivia, Bosnia and Herzegovina, Botswana, Brazil, British Virgin Islands, Brunei, Brunei Darussalam, Bulgaria, Burkina Faso, Burundi, Cambodia, Cameroon, Canada, Cape Verde, Cayman Islands, Central African Republic, Chad, Chile, China, Colombia, Comoros, Congo (Brazzaville), Cook Islands, Costa Rica, Croatia, Cuba, Cyprus, Czech Republic, Denmark, Djibouti, Dominica, Dominican Republic, Ecuador, Egypt, El Salvador, Equatorial Guinea, Eritrea, Estonia, Ethiopia, Falkland Islands, Fiji, Finland, France, Gabon, Gambia, Georgia, Germany, Ghana, Gibraltar, Greece, Grenada, Guam, Guatemala, Guernsey, Guyana, Haiti, Honduras, Hong Kong, Hungary, Iceland, India, Indonesia, Iraq, Ireland, Isle of Man, Israel, Italy, Jamaica, Japan, Jersey, Jordan, Kazakhstan, Kenya, Korea Republic of, Kuwait, Kyrgyzstan, Laos, Latvia, Lebanon, Lesotho, Liberia, Libya, Liechtenstein, Lithuania, Luxembourg, Macedonia, Madagascar, Malawi, Malaysia, Mali, Malta, Marshall Islands, Mauritius, Mexico, Moldova, Monaco, Mongolia, Montserrat, Morocco, Mozambique, Namibia, Nepal, Netherlands, Netherlands Antilles, Nevis, New Caledonia, New Zealand, Nicaragua, Niger, Nigeria, Niue, Norway, Oman, Pakistan, Panama, Paraguay, Peru, Philippines, Poland, Portugal, Puerto Rico, Qatar, rench Polynesia, Romania, Russian Federation, Rwanda, Saint Kitts and Nevis, Saint Lucia, Saint Vincent and the Grenadines, Samoa, San Marino, Saudi Arabia, Senegal, Serbia and Montenegro, Seychelles, Sierra Leone, Singapore, Slovakia, Slovenia, Solomon Islands, South Africa, Spain, Sri Lanka, Sudan, Suriname, Swaziland, Sweden, Switzerland, Syria, Taiwan, Tajikistan, Tanzania, Thailand, Trinidad and Tobago, Tunisia, Turkey, Turkmenistan, Turks and Caicos, Tuvalu, Uganda, Ukraine, United Arab Emirates, UUnited Kingdom, Uruguay, Uzbekistan, Vanuatu, Venezuela, Vietnam, Virgin Islands British, Wallis and Futuna, Yemen, Yugoslavia, Zambia, Zimbabwe