Launch airlines
Strictness high
AirAsia
AirAsia tends to be stricter than average about onward-travel documents.
Strictness medium
Cebu Pacific
Cebu Pacific is especially relevant for Philippine travel, where it runs active document and entry checks.
Strictness medium
Jetstar
Jetstar can carry a real document-check risk, especially on international leisure routes into destinations that require onward proof.
Strictness medium
Scoot
Scoot runs clear document-check steps on international travel, so onward-travel proof matters.
Strictness medium
VietJet Air
VietJet Air runs meaningful document checks on international routes, and is especially relevant across Southeast Asia.