The visa application process may take more than one month. International participants should know visa requirements and plan travel well in advance. You can request an invitation letter by completing our online form. Invitation letters are only issued to registered participants who have paid the CIKM 2025 registration fee. Applicants for a visa may require a copy of the Unique Number Certificate (i.e., Business Registration Certificate for non-profit organizations) of the Korean inviting organization. Please indicate your need for this document in the invitation letter request form or contact us directly. We can provide No PE certificates for Indian participants who require them for registration and tax purposes. Please note that we must first receive this letter from ACM, which typically takes at least one week to process. Therefore, participants requiring this certificate should plan accordingly and contact us via email with sufficient time. Please contact us at: cikm2025@easychair.org.