Foreign scholars who are planning a short-term visit to Tsinghua (such as for academic exchange or to attend an academic conference) for a duration of less than 3 months without salary are generally required to apply for a F Visa before entry into China. Since the maximum stay under an F Visa is usually 90 days, applicants need to have a clear-cut idea about the duration of their intended stay in China. After the host department/school/institution of Tsinghua University submits the application form to the International Students and Scholars Office (ISSC), the ISSC will issue the Invitation Letter of Duly Authorized Unit, which is required to apply for an F Visa. This application process generally takes 3-5 work days. The host department and applicant are both strongly advised to apply for the Invitation Letter at least 4 weeks prior to the foreign scholar’s scheduled arrival. This is so that the scholar has sufficient time to subsequently apply for his/her Visa at a Chinese consulate or embassy in his/her home country or other designated country.