The carrier said the impact of the coronavirus outbreak on demand for air travel was partly to blame for its collapse.
Its website now advises customers to “not travel to the airport” unless they have arranged an alternative flight.
Exeter-based Flybe narrowly avoided going bust in January.
In a letter to the airline’s staff, chief executive Mark Anderson said: “Despite every effort, we now have no alternative – having failed to find a feasible solution to allow us to keep trading.
“I am very sorry that we have not been able to secure the funding needed to continue to deliver our turnaround,” he added.
In response to the collapse, the UK government said it was ready to help Flybe’s workers find new jobs and would work with other airlines to replace services: “We are working closely with industry to minimise any disruption to routes operated by Flybe, including by looking urgently at how routes not already covered by other airlines can be re-established by the industry. “
How have passengers reacted?
David Manners arrived at Exeter Airport this morning to find his Flybe flight to Paris had been cancelled.
The trip had been planned as a surprise Christmas present for his wife and he said they were “absolutely gutted”.
Mr Manners, who lives in Lyme Regis, said Flybe’s collapse would also be bad for the area.
“We use this airport quite a lot because it’s so convenient,” he said. “We know some of the staff very well… I feel for them.”
Jessica, Abby and Robyn work for a recruitment agency and were due to return to Jersey via Exeter Airport after a business trip.
They described the airport as a “ghost town” on arrival.
Abby said: “I use Flybe maybe once a month, and not having it now will be such a nightmare.”
The group said that other airlines such as EasyJet or British Airways did operate flights from Jersey, but they typically only flew into larger airports such as London Gatwick.
Blue Islands has said it is operating a flight to Jersey from Exeter on Thursday afternoon as a gesture of goodwill.
What are your rights as a passenger?
Flybe customers who bought tickets directly from the company will not be protected by the Atol scheme.
However, if you went through a travel agent or other third party you might be covered.
Some people may be able to get their money back if they paid by credit card or with some debit cards.
What went wrong at the airline?
The carrier ran into difficulties last year and was bought by a consortium that includes Virgin Atlantic.
In January, the new owners said they would pump £30m into the business to keep it afloat, but appealed to the government for additional support.
Flybe, which served destinations from the Channel Islands to Aberdeen, had also been hoping for a £100m lifeline fom the government and changes to Air Passenger Duty taxes.
But the news that it may benefit from government help sparked a backlash from its rivals. British Airways’ owner IAG filed a complaint to the EU arguing Flybe’s rescue breached state aid rules.
Virgin Atlantic said it was “deeply disappointed” after Flybe went into administration. A spokesperson said that the consortium had invested more than £135m in keeping the airline flying for an extra year.
While its financial problems were already apparent the impact of the coronavirus on the travel industry had made a bad situation much worse.
Air transport expert John Strickland added that the regional market was extremely challenging for any airline, but that Flybe had made matters worse some years ago through over-ambitious expansion.
“It’s really too big for what it’s trying to do,” he said.