Passport and residential address changes
Report passport or residence changes to ICA within 14 days. Upload the new passport biodata page through the appropriate e-Service; update the address through the holder’s Singpass account. If the online route fails, use ICA’s enquiry form. For example, replacing a passport requires updating the new number even when the LTVP has not expired.
Official ICA source
Written independently from ICA’s English original. The linked source supplies the complete document and subsequent updates.