This guide is for anyone planning to set up a private security business anywhere in the United Kingdom. It covers manned guarding, door supervision, close protection, CCTV monitoring, key holding, and cash and valuables in transit (CVIT) services.

Private security is a regulated sector. The Security Industry Authority (SIA) licenses individuals who carry out security work, and operates a voluntary quality scheme for companies. Getting the regulatory foundations right before you trade protects you from criminal liability and positions your business for the contracts that generate revenue.

If you are already trading and need to check your ongoing obligations, start at the section on recruiting licensed staff.

The SIA regulates private security across the whole of the United Kingdom, including Northern Ireland, where compulsory SIA licensing has been in force since 1 December 2009. If you operate in Northern Ireland, the same SIA licensing and ACS arrangements apply, with one difference: vehicle immobilisation is a licensable front-line activity there but not in Great Britain.

1. Register your business

Before you can trade, you need a legal business structure. The choice affects your personal liability, tax position, and how clients perceive your business.

1

Choose your business structure

Most security businesses operate as limited companies because clients — particularly public sector buyers — expect it, and it limits your personal liability. A sole trader structure is simpler but exposes you to unlimited personal liability for claims. If you are unsure, take professional advice before registering.
2

Register with Companies House (limited company)

Register online at gov.uk. You will need a registered office address, at least one director, and a person of significant control (PSC) statement. If you choose sole trader or partnership, register with HMRC instead.
3

Register with HMRC for tax

Limited companies must register for Corporation Tax within 3 months of starting to trade. Register for PAYE before your first payday if you will employ staff. Register for VAT if your taxable turnover exceeds the current threshold, or voluntarily if it benefits your business.

2. Arrange insurance

Insurance is both a legal requirement and a commercial necessity in private security. Without adequate cover, you cannot lawfully employ staff and most clients will not engage you.

Requirements to start a private security business

Key requirements for starting a private security business in the United Kingdom, including company registration, mandatory and recommended insurance, SIA Approved Contractor Scheme registration, HMRC obligations, and workplace pension duties. The SIA has regulated private security across the UK, including Northern Ireland, since 1 December 2009.

Company registration: Register with Companies House (limited company) or HMRC (sole trader/partnership)
SIA individual licence: All directors and staff performing licensable activities must hold a valid SIA licence (GBP 204, valid 3 years)
Employers' liability insurance (mandatory): Minimum GBP 5 million cover required by law if you employ anyone
Public liability insurance (recommended): Typically GBP 1 million to GBP 10 million cover; required by most clients and contracts
Professional indemnity insurance: Recommended for consultancy, risk assessment, and CCTV monitoring services
SIA Approved Contractor Scheme (ACS): Voluntary but strongly recommended; required by most public sector and large commercial clients
HMRC registration: Register for PAYE, Corporation Tax (limited companies), and VAT if turnover exceeds GBP 90,000
Workplace pension auto-enrolment: Mandatory from first eligible employee; minimum total contribution 8 percent of qualifying earnings
DBS checks: Enhanced DBS checks required for all security operatives as part of SIA licence application
Geographic scope: United Kingdom-wide. The SIA has regulated private security in Northern Ireland since 1 December 2009; vehicle immobilisation is a licensable front-line activity in Northern Ireland only, and criminal-record checks for NI applicants use AccessNI.

Starting a private security business in the United Kingdom requires meeting both general business formation obligations and sector-specific regulatory requirements under the Private Security Industry Act 2001.

Mandatory requirements:

Register your business with Companies House (limited company) or notify HMRC (sole trader or partnership)
Obtain a personal SIA licence if you will carry out licensable security activities yourself
Ensure every operative holds a valid SIA licence for their role before they start work
Take out employers' liability insurance with a minimum cover of GBP 5 million (a legal requirement if you have any employees)
Register with HMRC for PAYE when you hire staff, and for Corporation Tax within 3 months of starting to trade (limited companies)
Set up a workplace pension scheme and enrol eligible staff (auto-enrolment duty under the Pensions Act 2008)

Strongly recommended:

Public liability insurance — most clients require this as a contract condition, typically GBP 1 million to GBP 10 million depending on the services provided
Professional indemnity insurance — particularly important if offering security consultancy, risk assessments, or CCTV system design
SIA Approved Contractor Scheme (ACS) registration — a voluntary quality mark assessed by a UKAS-accredited body, widely required for public sector and large commercial contracts
Compliance with British Standards: BS 7499 (static site guarding), BS 7858 (security screening of personnel), BS 7984 (key holding and response services)

Deploying unlicensed staff is a criminal offence under section 5 of the Private Security Industry Act 2001, carrying a maximum penalty of 5 years' imprisonment and an unlimited fine.

When choosing cover levels for public liability and professional indemnity, check the minimum requirements in contracts you plan to bid for. Many local authority and NHS contracts specify GBP 5 million or GBP 10 million public liability cover as a minimum. If you provide consultancy, risk assessments, or design CCTV systems, professional indemnity insurance protects you against claims for negligent advice.

Review your cover annually and whenever you add new service lines or increase your workforce.

3. Understand SIA licensing and the Approved Contractor Scheme

Individual SIA licensing is mandatory for anyone carrying out licensable security activities. The Approved Contractor Scheme (ACS) is voluntary but in practice essential for winning significant contracts.

You cannot apply for ACS approval until you have been trading for at least 12 months and can demonstrate that you supply at least 2 licensable operatives per activity. Use your first year to build the management systems, training records, and compliance processes that the ACS assessment will examine.

SIA Approved Contractor Scheme overview

Overview of the SIA Approved Contractor Scheme (ACS), a voluntary quality assurance scheme for companies providing private security services across the United Kingdom. Covers eligible activities, benefits, and the pass/fail approval model. The SIA has regulated private security in Northern Ireland since 1 December 2009, and the ACS applies there too.

Scheme type: Voluntary quality assurance scheme run by the Security Industry Authority (SIA)
Eligibility: Private security companies providing SIA-licensed activities in the UK for at least 12 months, supplying at least 2 licensable operatives per activity
Approval model: Pass or fail — no graded levels (no gold, silver, or bronze)
Approval scope: Granted per activity, not per company — a firm may be approved for door supervision but not security guarding
Criminal offence: It is a criminal offence to claim ACS approval or display the ACS accreditation mark when not approved
Geographic scope: United Kingdom-wide. The SIA has regulated private security in Northern Ireland since 1 December 2009, so the ACS applies there on the same basis as in Great Britain.
Eligible activities: Manned guarding (including cash and valuables in transit, close protection, door supervision, CCTV, security guarding), key holding, vehicle immobilisation

The SIA Approved Contractor Scheme (ACS) is a voluntary quality assurance scheme for companies providing private security services regulated by the SIA. Unlike individual SIA licensing (which covers individual operatives), the ACS approves companies.

Key benefits of ACS approval:

Listed on the SIA register of approved contractors, visible to buyers searching for security providers
Access to Licence Assist and Licence Management services for managing staff licensing
Licence Dispensation Notices (LDNs) — permission to deploy staff while their licence applications are being processed
Required for many public sector contracts, including all Scottish Government security contracts
Reputational advantage with local authorities, NHS trusts, and large commercial clients
Right to display the ACS accreditation mark on stationery, vehicles, website, and premises
May support negotiations with commercial insurers
Invitation to SIA-led regional forums sharing best practice and regulatory updates

Planning for ACS from day one

Even though you cannot apply for ACS in your first year, the assessment criteria should shape your business from the start:

Licensing compliance — build a licence management system that tracks every operative's licence number, sector, and expiry date
Training and development — document all training delivered, including induction, site-specific, and ongoing CPD
Quality management — implement documented procedures for incident reporting, complaints handling, and service delivery
Financial management — maintain transparent financial records showing the business is solvent and well managed

If ACS is a priority, consider the NSI ACS Passport Scheme, which combines NSI certification with a simplified SIA application route.

4. Recruit and deploy licensed staff

Deploying anyone without a valid SIA licence for the activity they perform is a criminal offence under section 5 of the Private Security Industry Act 2001. The offence applies to you as the employer or supplier, not only to the individual.

Employer obligations for SIA-licensed staff

Employer duties to verify SIA licence validity, the offence of deploying unlicensed security operatives under s.5 PSIA 2001, record-keeping requirements, and the due diligence defence.

Core employer offence (s.5 PSIA 2001): It is a criminal offence for a person to use or supply unlicensed individuals to carry out licensable conduct.
Licence verification tool: SIA online licence checker — employers must verify each operative's licence status before deployment.
What to verify: Licence validity, expiry date, correct sector (e.g. door supervision, CCTV, close protection), and right to work in the UK.
Record-keeping duty: Employers must maintain records of licence checks including operative name, licence number, sector, expiry date, and date checked.
Due diligence defence: Under s.5(2) PSIA 2001, it is a defence to show all reasonable steps were taken to verify the operative held a valid licence.
Ongoing monitoring: Employers should conduct periodic re-checks, not rely solely on the initial verification at point of hire.
ACS scheme advantage: SIA Approved Contractor Scheme (ACS) members demonstrate compliance through independent audit of deployment and licence management procedures.

Section 5 of the Private Security Industry Act 2001 creates a strict liability offence of deploying unlicensed security operatives. However, the due diligence defence under s.5(2) provides that if a person can prove they took all reasonable steps to establish that the operative held a current SIA licence, they are not guilty of the offence. Employers should use the SIA's free online licence checker before every deployment and retain auditable records of all checks performed.

1

Verify every licence before deployment

Use the SIA's free online licence checker to confirm the operative's licence is valid, covers the correct sector, and has not expired. Do this before every new deployment, not just at the point of hire.
2

Keep auditable records

Record the operative's name, SIA licence number, licence sector, expiry date, and the date you performed the check. These records are your evidence for the due diligence defence under s.5(2) if a licence issue arises.
3

Screen staff to BS 7858

British Standard BS 7858 sets out a thorough vetting process for security personnel, covering identity verification, employment history (minimum 5 years), criminal record checks, and financial probity. Following BS 7858 is expected by most clients and is assessed as part of ACS approval.
4

Set up ongoing monitoring

Do not rely solely on a check at hire. Re-verify licences periodically (monthly or quarterly) and before any change of assignment. If you hold ACS approval, the Licence Management service helps automate this.

5. Build your compliance systems

A well-run security business needs documented systems that cover both general employment law and sector-specific requirements. Getting these right early reduces risk, supports your ACS application, and gives clients confidence.

General business compliance

Workplace pension auto-enrolment — set up a pension scheme and enrol eligible staff from their first day of eligibility (minimum 8 percent total contribution on qualifying earnings)
PAYE and payroll — run payroll correctly, issue payslips, and submit RTI returns to HMRC
Right to work checks — verify every employee's right to work in the UK before they start
Health and safety — carry out risk assessments for each site and activity, and provide appropriate PPE and lone worker protections
GDPR compliance — if you operate CCTV systems or hold personal data about clients and staff, you need appropriate data protection policies and may need to register with the ICO

Industry standards

Adopting recognised British Standards strengthens your market position and is assessed during ACS approval:

BS 7499 — static site guarding and mobile patrol services
BS 7858 — security screening of individuals employed in a security environment
BS 7984 — key holding and response services

These standards are not legally mandatory, but most serious clients and all ACS assessing bodies expect compliance with the standards relevant to your service lines.

What next

Once your business is registered, insured, and you have recruited licensed staff:

Build your track record over the first 12 months while documenting your management systems for the ACS application
Apply for ACS approval once you meet the eligibility criteria (12 months' trading, at least 2 licensable operatives per activity)
Register on public sector procurement frameworks — many require ACS approval as a minimum
Review your insurance cover annually and before bidding for larger contracts
Keep up to date with SIA regulatory changes by subscribing to SIA news updates

If you are already operating and discover that any of your staff lack a valid SIA licence, remove them from licensable duties immediately. Continued deployment is a criminal offence regardless of whether you were aware of the licence gap.

Related guidance

Employers' liability insurance for detailed cover requirements
Workplace pension auto-enrolment for setting up your pension scheme
Right to work checks for verifying employees' immigration status

Start a private security business

Verify SIA licence validity for your employees

SIA employer compliance checklist

Register as an SIA Approved Contractor

Film and TV production permissions and insurance

Farm health and safety essentials

1. Register your business

Choose your business structure

Register with Companies House (limited company)

Register with HMRC for tax

2. Arrange insurance

3. Understand SIA licensing and the Approved Contractor Scheme

Planning for ACS from day one

4. Recruit and deploy licensed staff

Verify every licence before deployment

Keep auditable records

Screen staff to BS 7858

Set up ongoing monitoring

5. Build your compliance systems

General business compliance

Industry standards

What next

Related guidance

Official guidance and legislation

Related guides in Risk Assessment

1. Register your business

Choose your business structure

Register with Companies House (limited company)

Register with HMRC for tax

2. Arrange insurance

3. Understand SIA licensing and the Approved Contractor Scheme

Planning for ACS from day one

4. Recruit and deploy licensed staff

Verify every licence before deployment

Keep auditable records

Screen staff to BS 7858

Set up ongoing monitoring

5. Build your compliance systems

General business compliance

Industry standards

What next

Related guidance

Official guidance and legislation