Melbourne airport remains closed to international visitors, with incoming capacity for Adelaide and Canberra assessed on a case-by-case basis.

Between seven to eight international flights are scheduled to land each day at Sydney Airport. However, the cap per flight could increase if some scheduled services do not go ahead.

“The amount allocated to each airline for each flight varies depending on how many flights are operating on each day but within a total daily cap,” a spokeswoman for the federal Department of Infrastructure, Transport and Regional Development said.

“Airlines have the ability to request more than their per-flight passenger allocation on a particular day if there is any spare capacity available on that particular day.”

She also said airlines were required to enforce the limits on their own services at the point of departure overseas, and that while Border Force officials checked arrival numbers, no fines or breaches had been issued since the caps came into effect.

A Qatar Airways spokeswoman told the Guardian it “analyses each flight on a case-by-case basis to ensure we facilitate onward travel to the final destination for as many passengers as possible.”

“The passenger list is continually assessed and based on a range of criteria, including compassionate and medical requests, connecting flights, booking class, party size etc. We continue to work closely with our passengers to find alternative flights if they are unable to travel on their original intended flight,” the spokeswoman said.

An Etihad spokesman said government advice had indicated the caps would be in place until at least mid-August, and that they had been told to operate to a 30 passenger per flight limit into Sydney. The airline continues to fly a passenger jet as a freight-only service on its Abu Dhabi to Melbourne route.

A Singapore Airlines spokesman said “should any of our flights have a booked capacity over the government arrival cap, we will work with affected customers to re-accommodate them accordingly”.