Serco is a multinational outsourcing company that provides outsourced public services and security services. In the UK, Serco operates in a number sectors of public service provision:

• Health services, including NHS and GP services
• Transport, including train services on Merseyside and the north of England, in partnership with Abellio
• Prisons and justice, where it was banned from further government contracts after overcharging on electronic tagging contracts
• Immigration and border control, including the infamous Yarl's Wood detention centre
• Defence, mainly maintenance contracts.​
• Shared and back-office services for local councils

Serco is a UK-based plc that is listed on the London Stock Exchange.

Serco was forced to pull out of a contract to provide out-of-hours GP services in Cornwall after it emerged that the company had been falsifying data and that it had a ‘bullying culture' which discouraged whistleblowing in the interests of patients.

​Sodexo Justice Services is a subsidiary of Sodexo, a French multinational food, facilities and justice services multinational based in Paris.

In the U.K. Sodexo Justice Services provides a range of custodial and post-release services to the UK Ministry of Justice, particularly design, construction, management and financing of contracts for PFI prisons. It directly operates 5 UK prisons.

Sodexo also runs 6 of the 21 regional Community Rehabilitation Companies set up the Government following the privatisation of probation services in 2015.

Amey works for local and central government delivering services such as highways and rail management and maintenance, facilities management, waste collection and treatment and other utilities services. 

It has recently been thrust into the spotlight because of its role in tearing down trees in Sheffield, despite a strong protest campaign by locals.

Carillion plc was a British multinational facilities management and construction services company headquartered in Wolverhampton, United Kingdom. It is listed on the London Stock Exchange.

Carillion dramatically collapsed in January 2018 following multiple warnings about its financial situation.  It had public sector contracts in construction, tagging prisoners, building hospitals and schools, and providing school lunches.

It has dozens of subsidiary companies, a few of which are involved in NHS service provision. The most notorious is Clinicenta, who ran a hospital in Stevenage, and had their license revoked by the Care Quality Commission in 2013 after failing to provide a safe level of care to patients.