All travelers must have a passport that will be valid for at least six months after the end of their vacation. If you will be staying for fewer than 21 days, you will not be required to get a visa, but longer stays will require one. A tourist visa will allow you to access the country, but will not allow you to conduct business or attend school within its borders.
You also will be subject to a fee for the tourist visa. According to the government of the Commonwealth of Dominica in 2010, this fee is $52. You must provide two passport-size photos, proof of employment, a copy of your bank statement, a letter of invitation from a Dominican native and a completed visa application. Finally, you must have an ongoing plane ticket to leave the country.
For businesspeople traveling to Dominica, the passport requirement is the same as it is for tourists; passports must be valid for six months after your date of departure from Dominica. If you will be staying for longer than 21 days, then you will need a business visa. The conditions for a business visa are the same as those of a tourist visa.
A copy of the visa application is on the Commonwealth of Dominica's website, dominica.gov. You may also apply for a visa through visa and passport processing agencies, such as Travisa and Travel Document Systems. American passports are issued at your local post office.
If you are traveling through Dominica --- in transit --- you need to have a only valid passport that is valid for six months beyond your departure date and a plane ticket departing from the country. The plane ticket must be for a flight that leaves the country in fewer than 21 days.
There are some exceptions to the length-of-stay requirement, depending on what country your passport was issued in. American citizens can enjoy up to six months of vacation in Dominica without a visa, as can citizens of CARICOM member countries and countries in the Commonwealth of Nations, including Australia, the United Kingdom, India, South Africa and Canada. CARICOM, or Caribbean Community, is a group of 15 nations designed to promote integration within the area.
In addition to these countries, there is a list of other countries whose citizens can stay in Dominica for up to three months without a visa. This list includes many European, Asian and South American countries, including those that have friendly relations with Dominica. This list is on the Commonwealth of Dominica's website.