Spanish-based airline LTE International has suspended operations after telling Spanish authorities that it was in serious financial difficulty.
LTE's website stopped taking bookings late on Thursday after it said it could not cover costs for the next few days.
LTE runs flights from Spain to the UK, Italy and Saudi Arabia. It has 300 staff and a fleet of seven Airbus 320s.
Some UK passengers were holidaying in Tenerife with Cosmos, which has laid on a flight to get them home.
A Cosmos statement said: "Passengers currently in Tenerife who were due to return to Birmingham at 1125 and to Glasgow at 1735 today will now be flying on a Monarch Airlines flight into Manchester this evening, departing Tenerife at 2345, and will be transferred by coach for their onward journey to Birmingham and Glasgow.
"Passengers due to fly from Birmingham to Tenerife at 1225 lunchtime today will be transferred by coach to connect with the Monarch Airlines flight departing from Manchester at 1830 this evening.
"Passengers who were due to fly from Edinburgh to Tenerife at 0035 tomorrow, 18 October, are currently being contacted and will be offered a full refund or the opportunity to fly from Manchester on this evening's departure at 1830, returning to Manchester on 25 October."
Cosmos said about 320 people were due to travel back to the UK on Friday, with another 350 due back at a later date.
LTE issued a statement saying that it was doing "everything to minimise the impact of this suspension of services" on its customers.
"After 20 years operating with maximum dedication to our clients, it just was not possible to avoid this situation, given world events lately," the firm said on its website.
Airline employees were told of the company's difficulties via text messages on their mobile phones.
The Spanish Civil Aviation Authority is due to decide whether to suspend LTE's operating licence.
Problems in the aviation industry have already brought down a series of small airlines over the past year.
The most serious collapse came in September, with the demise of XL Airways and its parent firm, the UK's third-largest tour operator.