Before departure
ICA advises at least six months’ passport validity for overseas travel, good physical condition and the destination’s required visa. Damaged/tampered passports can cause problems abroad. Record the itinerary in the official eRegister channel linked by ICA so consular assistance can reach you during emergencies.
Overseas checks and returning
Check passport endorsements on arrival and departure abroad; raise discrepancies with the foreign police/immigration authority. For a Singapore citizen returning to Singapore, a Singapore passport with less than six months’ validity is accepted for arrival clearance. That return rule does not determine another country’s entry requirements.
Official ICA source
Written independently from ICA’s English original. The linked source supplies the complete document and subsequent updates.