Judges say the government does not have to publish more information on how it decides its traffic light system, after a legal challenge brought by Manchester Airport Group and five airlines failed.
Travel sector firms had been pushing in court for more transparency, arguing that decisions on which countries were on the list were not based on data.
But the High Court ruled the government had not acted unlawfully.
The traffic light system rates countries based on to their Covid risk.
The judges said that in many cases providing the detailed information requested when the traffic light list changed “would impose an unreasonable burden” and “risk slowing the decision-making process”.
The legal challenge was brought by Manchester Airport Group (MAG) and Ryanair, IAG, Tui, EasyJet and Virgin Atlantic, who have all been calling for more transparency about how decisions are made.
Ryanair, EasyJet, Tui, Virgin Atlantic, and IAG, the owner of British Airways, had backed the case.
The firms had been calling for more transparency about how the government decides which countries qualify for the green list of safe places to visit amid the pandemic.
They had criticised the traffic light system of classifying countries based on their Covid-19 risk, saying decisions are not based on data, and saying last minute changes have hurt bookings.
While the judges accepted part of the argument against the government, it will not have to disclose more information on how it reaches decisions over its travel rules.
Ministers previously said the system “cautiously manages the risk of new variants”.