Singapore Airlines, via its official website, reported (Sep-2021) all travellers departing for transit through Singapore are required to take a pre-departure COVID-19 PCR test within 48 hours before the scheduled departure date of their flight, effective 09-Sep-2021. Travellers who have remained in Hong Kong, Macau, Mainland China and Taiwan in the past 21 days are exempted from the pre-departure COVID-19 test.
SIA: Travellers transiting through Singapore to take pre departure PCR test
7 September, 2021