There is no strict critical or official deadline for filing a request for substantive examination in Cambodia.
The Cambodia Department of Intellectual Property (DIP) does not have the infrastructure to conduct local examination. Instead, once the application has been examined for formality requirements by the Cambodia DIP, it will be sent to foreign patent offices for substantive examination.
It is possible to accelerate the prosecution of a Cambodian application to grant by providing the granted claims of a corresponding application (by USPTO, EPO, KIPO, or JPO) or via the ASPEC programme. The Applicant may also wish to file an application in Singapore, and re-register a patent in Cambodia based on the granted Singapore patent (based on the agreement between Singapore’s IPOS and Cambodia’s Ministry of Industry and Handicraft).