An estimated 150,000 people were on Thomas Cook holidays as last-ditch talks to save the company failed.
But travellers have described having mixed experiences, with some only hearing about the collapse from the news and others continuing their travel plans with very few changes.
Some have also faced demands for payments from hotels owed money by Thomas Cook, one of which reportedly held visitors "hostage" in Tunisia, although most people who booked packages should be covered by the ATOL scheme.
One such person is a holidaymaker from near Stafford, who says her hotel in Greece has started locking people out of their rooms if they refuse to pay.
'Locked out of rooms'
The traveller, who asked to remain anonymous, is staying at the Magnolia Resort in Katelios, Kefalonia, and found out about the firm's collapse on the news the day before she was due to travel home.
She and her partner have so far refused to pay, due to the risk of losing the money paid to Thomas Cook and the hotel, and are planning to get a taxi to the airport in case their transfer doesn't turn up.
She said: "We could now have to pay for our hotel. They are not protected by ATOL and haven’t received any money from Thomas Cook since June.
"We have no idea if the coach will turn up tomorrow and we are an hour away from airport.
"We are totally relying on CAA website as there is no information coming from anywhere.
"The cost of the hotel is €700 per week so €1400 for us - a lot when we have already paid.
"A few people here have refused to pay and been locked out of their rooms."
Lynsey Rathbone, from Walsall, is due to fly home with around 20 people on Thursday from Zante.
The group took a 10-day holiday on the Greek island but have heard nothing since Thomas Cook's collapse – instead having to watch the news for information.
"I think it's just a waiting game now," she said.
'No moaning from us'
However Jade Common, from Hednesford, was expecting a smooth journey home from Zante on Monday after a replacement flight was put on for the same time her Thomas Cook flight had been planned.
Ms Common is in Greece celebrating the 10th anniversary of her business Jabu Hair Studio with friend Amy Darby.
The 35-year-old said: "We're due to fly home at 12.45pm today. Our hotel and Thomas Cook reps were all working this morning.
"We have had a coach transfer turn up and our Birmingham flight is still going ahead.
"We’ve checked our luggage in and Titan Airways have took over.
"We’re flying at the same time and in the same seats that we paid and pre-booked too. No moaning from us here. Fantastic so far.
"It's been a better experience than usual if I’m honest. Same flight, allocated seats and scheduled on time. It's too good to be true at the moment.
"Myself and my friend Amy Darby have spent a week here celebrating being 10 years in business.
"We’ve had a blast but this news over the last three days has put a slight dampener on the holiday.
"We just want to get on that plane and home to our loved ones."
Turkey trip cancelled for Codsall couple
Anita Green and husband Dwaine, both from Codsall, were due to leave for Dalaman in Turkey this morning.
But their £800 holiday plans were scrapped after news of the travel giant's collapse reached them.
Mrs Green explained: "We booked it through the travel agents Co-op in Codsall.
"We watched the reports last night and I went on the internet and it was not saying anything – it was like it would be normal.
"We thought the reports were just scaremongering and when I woke up I saw it had collapsed."
The 34-year-old received a call just after 9am from the travel agents, who apologised and asked them to come in to book a new flight.
But the cost – which had risen by £500 – was too much for the couple to fork out.
Anita added: "We've been packing over the last few days and it's been really exciting – it's nice to look forward to something.
"But we've only lost a holiday – staff have lost their jobs, it's their lives."
All quiet in Birmingham
By Megan Archer at Birmingham International Airport
It’s usually frantic and bustling with excited holiday-goers - but today the Thomas Cook check-in desk at Birmingham Airport is eerily quiet.
The announcement that the company had collapsed had come at 2am - a brief message popped up on all screens surrounding the departure zones, reading that Thomas Cook had ceased trading. And any unfortunate passengers waiting for a flight were handed a leaflet explaining their next steps.
Among those passengers were Great Wyrley friends Nathan Clarke, Matt Pritchard, and Sam Gadd.
The young group, aged 18-20, had been excited to fly off to Bulgaria for a “lads holiday”.
Aware of the trouble Thomas Cook was facing, they were expecting the company to collapse at 8.30am, they said. And with their flight booked for 5.30am, it looked like they could have just made it.
“We got here at 12am, but then at 2am that message appeared on all the screens and a security guy started handing these leaflets out,” Nathan, aged 18, said.
“We’re gutted but hey, what can we do about it? There’s nothing to do but help try and and get another flight.”
Matt, aged 20, an apprentice accountant, spoke to the Express & Star at 10.30am having been at the airport for nearly 11 hours.
He was on hold to Love Holidays while he spoke and said they might be lucky enough to get a flight with TUI at 4.15pm.
He said: “We saw the crew come in too but then they all had to leave. They obviously had no idea and looked really upset.
I’m reporting from @bhx_official this morning after the collapse of @ThomasCookUK - travellers are due to arrive here later today. And all flights outbound from the airline are cancelled. Have you been affected? Please tweet me to chat! More on the story via @ExpressandStar pic.twitter.com/EmuNJZxAbS— Megan Archer (@MeganA_Star) September 23, 2019
“We were on this holiday for Sam’s birthday - he turned 19 yesterday and we were doing to do a bit of everything on this trip.
"Beach, clubbing and this thing called paint party. I went when I was 18 but was really ill so couldn’t do it, and I’ve always wanted to do it since.”
It was also due to be computer programmer student Nathan’s first trip on an aeroplane.
Update on these 3 Staffordshire lads Sam, Matt & Nathan - who got to @bhx_official at 12am for Bulgaria flight. Sadly not able to reschedule their holiday. Nathan said they will “try again next year”. It was due to be his 1st time on a plane too. Gutted for them ☹️ #ThomasCook pic.twitter.com/4oPU8hsCQ0— Megan Archer (@MeganA_Star) September 23, 2019
“We’re a bit disappointed,” added Sam, also an apprentice accountant. “Feels like we’ve been here a long time.”
The friends all paid about £500 each for their all inclusive week-long holiday to Burgas, in Bulgaria. But Sam said luckily they were protected by ATOL.
After waiting 12 hours they were advised to head home - and the airport paid for their taxi back to Staffordshire.
Later that afternoon Nathan told the Express & Star: “Unfortunately we were not able to get another holiday straight away as the arrangements had been cancelled. We are planning to retry again for next year.”
Flights were due to come in at about 12pm and 1pm with Thomas Cook passengers - but delays quickly flashed up on the screen.
Finally, travellers arrived from Mahon and Zykanthos at the same time of about 2.25pm - as the CAA desperately tried to get stranded holiday makers home.
Another flight from Burgas also came in at 5.25pm.
Birmingham Airport advice
A spokesman for Birmingham Airport said: "It is with regret that we have been notified this morning that Thomas Cook Airlines has ceased trading with immediate effect.
"Our priority is to support these passengers who were scheduled to travel from Birmingham Airport today by providing extra support staff, information and assist with their arrangements home.
It is with regret that we have been notified, this morning, that Thomas Cook Airlines has ceased trading with immediate effect. Our priority is to support passengers that were scheduled to travel from Birmingham Airport. For information please visit: https://t.co/DEv77KuPYQ— Birmingham Airport (@bhx_official) September 23, 2019
"We’re working closely with the CAA and the DfT to also support the effort to repatriate customers back to the UK over the coming weeks.
"Passengers due to travel with Thomas Cook are advised not to come to the Airport as there will be no more Thomas Cook flights from the UK.
"Anyone booked to travel with Thomas Cook should visit thomascook.caa.co.uk or call 0300 303 2800 from within the UK or +44 1753 330330 from overseas.
"Thomas Cook has been a partner airline of Birmingham Airport for many years, carrying 750,000 passengers annually. It was Birmingham’s fifth largest carrier and based 4 aircraft at the airport."