Under the Enlistment Act (Chapter 93), all male Singapore citizens and Permanent Residents aged 13 years and above are required to comply with the Exit Permit requirements.
Application for exit permit or renewal of exit permit can be done through the internet at http://www.ns.sg using your SingPass.
Any advice relating to absence from Singapore can be sought from:
Exit Permit Office
Central Manpower Base
3 Depot Road
Tel: (65) 6567-6767