Frequently Asked Questions about top five security companies in UK

1. Who are the top five security companies in the UK?

Measured by 2023 UK guarding-sector turnover, the leaders are Mitie, Allied Universal/G4S (including TSS), OCS Group, Bidvest Noonan and Securitas UK. (Infologue Top 100 UK Security Companies 2023)

2. Is Mitie bigger than G4S in the UK?

Yes. Mitie’s security division booked about £935 million in 2023, versus roughly £633 million for G4S’s UK arm, making Mitie the larger domestic player. (Infologue Top 100 UK Security Companies 2023)

3. Which security company pays the most in the UK?

Among employers advertising front-line “security-officer” roles, the Metropolitan Police Service consistently tops the pay tables, with typical packages in the mid-£30 thousands and specialist posts rising to the high-£50 thousands. (Metropolitan Police Security Officer salaries: How much ... - Indeed, Metropolitan Police Service Cyber Security Salaries - Glassdoor)

4. What is the biggest fire-and-security company in the UK?

Industry analysts list ADT Fire & Security plc (Johnson Controls) as the market-share leader in UK security-system services, ahead of rivals such as Chubb. (Security System Services in the UK Number of Businesses 2013-2031)

5. How much is a security officer paid in the UK?

The National Careers Service gives a typical range of £20,000 – £35,000 a year (roughly £10–£15 per hour) for licensed security officers. (Security officer | Explore Careers)

6. What is the oldest security company in the UK?

That distinction belongs to Corps Security (originally the Corps of Commissionaires), founded in 1859. (Corps Security History)

7. Who is the biggest security company worldwide?

Globally, Allied Universal—owner of G4S—leads the sector with around 800,000 employees and revenue exceeding US $18 billion. (Allied Universal)

8. Who is “in charge” of security in the UK?

For the private-security industry, statutory regulation sits with the Security Industry Authority (SIA), an arm’s-length body of the Home Office that licenses individuals and approves contractors. (Register of Approved Contractors - SIA Website)

9. What is the highest salary of a G4S security employee?

Mainstream officer roles average in the high-£20 thousands, but supervisory and shift-manager posts can reach £40 k-plus, with Indeed listings quoting up to £43 k. (G4S salaries: How much does G4S pay in the United Kingdom?)

10. What is the new name for G4S?

The company continues to trade as G4S, but since April 2021 it has been a wholly-owned subsidiary of Allied Universal. (G4S saga ends as shareholders accept $5.3 billion Allied Universal ...)

11. Is Mitie a big company?

Definitely. Group revenue is about £4 billion and its security arm is the UK’s largest, serving everything from retail estates to critical national infrastructure. (Infologue Top 100 UK Security Companies 2023)

12. Who are the top five security companies in the UK?

See answer 1 above—Mitie, Allied Universal/G4S, OCS, Bidvest Noonan and Securitas. (Infologue Top 100 UK Security Companies 2023)

13. Who bought G4S?

US-based Allied Universal completed the £3.8 billion takeover of G4S in April 2021. (G4S saga ends as shareholders accept $5.3 billion Allied Universal ...)

14. Is Mitie a security company?

Mitie is a facilities-management group; its dedicated Mitie Security division provides guarding, risk consulting, cyber and technology-led protection services—making it very much a security provider.

15. Who is the highest-paid employer in UK security?

For uniformed roles, the Metropolitan Police Service pays the most. For private-sector guards, Harrods is a standout, offering £32 k-£45 k for “uniformed security officer” positions. (Harrods Security Salaries - Glassdoor)

16. How much do bodyguards (close-protection officers) get paid in the UK?

Day rates typically run £150 – £300+, equating to about £35 k-£75 k annually for full-time work, depending on client risk level and location. (Bodyguard | Explore Careers | National Careers Service)

17. Which company is “best” for security?

“Best” depends on need: Mitie for scale and tech innovation; Allied Universal/G4S for global reach; Securitas for AI-enabled guarding; Corps Security for heritage sites; or niche close-protection specialists for VIPs.

18. Who owns G4S UK?

G4S UK is owned by Allied Universal Topco LLC, headquartered in California. (Allied Universal)

19. How many security companies are there in the UK?

IBISWorld counts about 6,400 private-security service businesses in 2024, while roughly 750 firms hold SIA Approved-Contractor status. (Private Security Services in the UK Number of Businesses 2013-2031, Register of Approved Contractors - SIA Website)

20. Is there a shortage of security officers in the UK?

Yes. Trade bodies estimate the industry needed to recruit around 62,000 additional licensed officers in 2023 to meet demand. (UK needs 62000 new security officers to ensure public safety in 2023) 

21.  Which is the best security company in the UK? 

There isn’t a single, one-size-fits-all “best” security company in the UK—because “best” hinges on what you need.  If your brief is a national, multi-site contract that demands heavy investment in AI analytics, 24 / 7 control-rooms and the ability to surge hundreds of licensed officers at short notice, Mitie Security is the standout choice.  It tops the 2023 Infologue revenue table, leads on technology trials such as drone patrols and was a joint-winner of Outsourced/Contract Security Team of the Year at the 2023 Security & Fire Excellence Awards for its BBC contract.  (Infologue Top 100 UK Security Companies 2023, Winners 2023 | The Security and Fire Awards for Excellence)

If personal, white-glove service and tight contract management are your priorities, a mid-sized specialist can outperform the giants.  Unitrust Protection Services was named Security Guarding Company of the Year (Under £35 m Turnover) at the 2024 Security & Fire Excellence Awards, a judges’ nod to its 98 % shift-fill rate and single-digit staff turnover.  (Celebrating Unitrust's legacy and success)

For critical-infrastructure and construction environments, many clients point to First Response Group (FRG).  FRG lifted the 2024 UK OSPAs trophy for Outstanding Contract Security Company after independent auditors praised its rapid-deployment teams and data-driven risk reporting.  (First Response Group Takes Home Top OSPAs Award to Represent ...)

If external accreditation is your yard-stick, look at firms in the elite ACS Pacesetters club—only the top 15 % of SIA Approved Contractors achieve the required audit score.  Companies such as Corps Security (founded 1859) hold that badge alongside NSI Guarding Gold and consistently rank at the top of customer-satisfaction polls.  (Corps Security - ACS Pacesetters)

In short, choose Mitie for scale and technology leadership; Unitrust for boutique, high-touch guarding; First Response Group for agile, high-risk sites; or an ACS Pacesetter like Corps when heritage, social value and audited quality matter most.  The “best” company is the one whose strengths line up with your specific risk profile, budget and service-level expectations.