While planning your trip to the Islamic Republic of Iran remember to double check your passport or any travel documents to be valid for at least 90 days. For some nationalities a valid Iranian visa is required and depending on your nationality, some can stay as a tourist up to 3 months per entrance. If you need a visa, it is highly recommended to start the visa process at least two months before your visit schedule.
If you are planning to experience the Persian heritage and celebrate Nowruz in Iran, bear in mind Nowruz holidays are hot-seasons in Iran and you have to submit your visa application before 8 March to avoid being stalled in the process. As a part of a tourism development program, Iran waived nationals of about 65 countries.Citizens of those countries are granted a 15-day tourist visa upon arrival (Airport Visa).
To Get More Info: http://evisa.mfa.ir/en/