Private firms are making increased profits as the government pays millions of pounds a day to put up asylum seekers in the UK, the BBC has learned.
BBC News has been told 395 hotels are being used to house asylum seekers, as arrivals to the UK rose last year.
Documents show one booking agency used by the Home Office trebled its pre-tax profits from £2.1m to £6.3m in the 12 months up to February 2022.
The Home Office says the asylum system is under "incredible strain".
The government has never publicly confirmed the number of hotels involved, but a government source told BBC News it is now using 395 to accommodate more than 51,000 asylum seekers, at a cost of more than £6m a day.
Of those hotels, 363 are in England, 20 in Northern Ireland, 10 in Scotland and two in Wales.
It means Northern Ireland and England have far more hotels housing asylum seekers per head of population than Scotland and Wales.
The use of hotels has increased exponentially as the number of people claiming asylum in the UK has increased, reaching a near 20-year high of 74,751 last year, according to Home Office data.
Asylum applications to the UK peaked at 84,132 in 2002, but then fell sharply to a low of 17,916 in 2010.
Small boat arrivals, accounting for about 45% of asylum applications in 2022, were also at record levels and the backlog of asylum cases now amounts to about 166,000 people.
Because of a lack of other suitable accommodation, asylum seekers are housed in hotels, which are often taken over by the government with only a few days' notice.
The BBC has been told existing bookings at some hotels, including business conferences and weddings, have been cancelled at short notice.
Hotel owners are approached to hand over their properties to outsourced companies, which run the business on behalf of the Home Office.
Three large firms have contracts to run the hotels.
One, Serco, provides some 109 hotels in England, according to a High Court judgement from December 2022, mostly in the Midlands, East and North West.
Serco, which also provides other services on behalf of the government, references "growth" in its immigration work in its 2022 annual report.
Court documents have revealed Mears Group is running 80 hotels in north-east England, Scotland and Northern Ireland. According to its annual report, the company increased its annual revenue by 22% in 2021.
The report said the increase was "largely driven" by its work finding hotel accommodation for asylum seekers.
Home Office spending records show a smaller firm, Calder Conferences, received £20.6m in payments from the Home Office in 2021 to book hotels. That figure increased to £97m in 2022.
Home Office sources suggested this work related principally to finding bridging hotels for Afghan refugees who arrived following the Taliban takeover in 2021.
Leeds-based Calder's annual accounts for the year ending February 2022 show turnover increased from £5.98m to £23.66m. The firm's pre-tax profits trebled, from £2.1m to £6.3m.
Calder's director, Debbie Hoban, saw her annual remuneration increase from £230,000 to £2.2m.
The firm has not responded to the BBC's request for comment.
The choice of hotels appears indiscriminate. BBC analysis found contracts with ones at airports, golf courses, country houses, the seaside, and some used for city business workers.
Some towns, Swindon for example, have more than one hotel housing asylum seekers, others have none.
UK government sources complain that Scotland's government has actively blocked hotels being booked for asylum seekers in the country. But the Scottish government said in a statement that because the asylum system is not devolved, the backlog was "of the UK government's own making".
Communities have spoken of their anger about the lack of consultation before asylum seekers moved in. There have been some protests, with far-right elements involved.
At the Wiltshire Leisure Village, a retirement complex near Royal Wootton Bassett, asylum seekers have been housed at a nearby hotel and fences erected, meaning residents of the leisure village do not have access to the golf course.
Fredricka Reynolds, a florist, lost her regular work for a hotel in Kegworth, Leicestershire, when asylum seekers moved in last month.
She said: "They rang me on the Thursday, before the asylum seekers came on the Monday and cancelled all my weddings for the foreseeable [future]."
The hotel is a major part of life for the village of about 4,000 people. Its swimming pool and gym, used by local people, have been closed.
"I understand they need housing, but then also why Kegworth? Why the main business in Kegworth that brings many people to the village, a lot of money into the village? It's all gone now," said Ms Reynolds.
Security guards often stop journalists approaching the asylum seekers, but two men living in the Wiltshire hotel spoke of their boredom.
Simpay Khalifa, a 25-year-old Sundanese man who arrived by small boat from France in November, said the hotel was "far from civilisation".
"There is nothing to do actually. We have to take a bus to get to Swindon. We need something to do like, for example, study some English courses," he said.
"Some people volunteer and do some charity work, but there is nothing to do here. Nothing. We stay the whole day at the room doing nothing."
The BBC used Freedom of Information requests to ask all UK councils how many hotels were being used for asylum seekers and how many individuals were living in them.
Of the 398 councils approached, 320 responded. The majority said there were no hotels or asylum seekers in their area, or referred the BBC to the Home Office.
One authority refused the request on the grounds it could lead to asylum seekers being exposed to "harassment, threats and physical or mental harm".
However, another council not only provided the number of hotels and individuals, but the address of a hotel.
A Home Office spokesperson said the government was "committed to making every effort to reduce hotel use and limit the burden on the taxpayer".
Additional reporting by Sam Francis and Rob England
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