While it is not mandatory to apply for patent protection in Singapore first before seeking protection overseas, national security clearance may be required. Section 34 of the Singapore Patents Act states that any person resident in Singapore is required to obtain a written authorisation from IPOS before the person files or causes to be filed outside Singapore an application for a patent for the same invention. 

The only exception to this is a patent application that has been filed in Singapore for 2 months or more and there is no direction from IPOS under Section 33 of the Patents Act. Contravention of Section 34 is a criminal offence.