Four passengers have been fined £10,000 for failing to declare they had travelled from a “red-list” country, West Midlands Police has said.
The passengers were stopped at border control by officials and were not able to leave Birmingham Airport.
All British and Irish citizens and UK residents who arrive in England after being in a country deemed a high Covid risk have to self-isolate in hotels.
The “red list” of 33 countries includes Portugal, Brazil and South Africa.
By 12:00 GMT on Monday, four passengers had been fined £10,000 under the new rules which came into force that day, a senior officer from the force told a meeting of the local Strategic Policing and Crime Board.
It is understood they were fined individually.
Birmingham Airport is one of five in England where people requiring hotel quarantine can enter the UK.
Those who fail to quarantine in hotels when required face fines of £5,000 to £10,000, while anyone who lies on their passenger locator form about having been in a country on the red list faces a prison sentence of up to 10 years.
It was not clear in the meeting which country or countries the fined parties had been in.
The regulations, which aim to stop coronavirus variants entering the UK, apply to arrivals who have been in a red-list country in the past 10 days.
Just four flights touched down in Birmingham on Monday, including a plane from Istanbul with about 100 passengers, some of whom were believed to be from a red list country.
The other four airports where those who must quarantine may enter the UK include Heathrow, Gatwick, London City and Farnborough.