Visas are required for entry into Turkey by nationals of most countries. However, E-Visa system allows nationals of 103 countries to easily obtain their e-Visas online in approximately three minutes and citizens of 89 countries can enter Turkey without any visas for 30, 60 or 90 days.
For e-visa service applicants just need to log on to www.evisa.gov.tr , provide the requested information, (after the application is approved) make online payment and download their e-Visa.
You may find the latest information about visa procedure in http://www.mfa.gov.tr/visa-information-for-foreigners.en.mfa
An official letter of invitation will be sent to you upon request.The invitation letter may be used by visitors to raise travel funds or to obtain a visa, but is not a commitment on the part of the organisers to provide any financial support.