Illegal Workers In The UK: Employer Responsibilities

Hiring the right people is exciting - but in the UK, you also have a clear legal duty to prevent illegal working. Getting this wrong can be expensive and, in serious cases, criminal.

The good news? With the right checks and records from day one, you can hire confidently and reduce risk across your business.

In this guide, we break down what “illegal worker” actually means under UK law, the penalties for employers, how to run compliant Right to Work checks, and what to do if a problem crops up on your watch.

What Counts As An “Illegal Worker” Under UK Law?

Under the Immigration, Asylum and Nationality Act 2006 and Immigration Act 2016, a person is working illegally if they don’t have permission to carry out the work in question in the UK - either because they have no immigration status, their leave has expired, or their visa conditions don’t allow the type of work or number of hours you’re offering.

In practice, this can include situations where:

• Someone has no permission to work in the UK at all.
• Their previous permission has lapsed or been curtailed.
• The visa permits work but not the role you’re offering (for example, working beyond restricted hours or in a different occupation code than allowed).
• They’re using false or someone else’s identity documents.

As the employer, you’re expected to run and keep records of Right to Work checks before employment starts and when permission is time-limited. If you follow the Home Office process correctly, you usually establish a “statutory excuse” - a legal defence against a civil penalty if it later turns out the employee wasn’t allowed to work.

Immigration enforcement has sharpened in recent years, and regulators are targeting businesses that cut corners. For context on current enforcement trends, see the government’s recent focus on compliance with visa rules for employers. It’s a helpful reminder that the Home Office looks at patterns across sectors and supply chains, not just one-off hires here.

Penalties And Risks For Employers

Employers face a mix of civil and criminal risks if they employ an illegal worker or fail to run proper checks.

1) Civil Penalties

The Home Office can issue a civil penalty of up to £60,000 per illegal worker (higher for repeat breaches) where you’ve employed someone who doesn’t have the right to work and you can’t show a valid statutory excuse.

In addition, you can expect:

• Public naming in Home Office “penalty lists”.
• Impact on any current or future sponsor licence applications.
• Disruption, inspections and potential loss of key staff.

2) Criminal Liability

It’s a criminal offence to employ someone you know, or have reasonable cause to believe, doesn’t have permission to work. Conviction can carry an unlimited fine and up to 5 years’ imprisonment for individuals involved. “Reasonable cause to believe” is a lower bar than many assume - if warning signs are ignored, the risk increases.

3) Sponsorship And Licensing Consequences

If you’re a licensed sponsor, illegal working can lead to suspension or revocation of your sponsor licence, with serious business interruption. If that’s a live risk for you, it’s worth understanding what happens when a sponsor licence is revoked and how to stabilise quickly if that occurs here.

Right To Work Checks That Actually Protect You

The only way to rely on a statutory excuse is to follow the Home Office’s Right to Work (RTW) process precisely. Here’s the plain-English version of what that looks like today.

Step 1: Choose The Correct Type Of Check

The correct route depends on the person’s status:

• Online check (share code): Required for individuals with a Biometric Residence Permit (BRP), Biometric Residence Card, Frontier Worker Permit, or eVisa. The candidate provides a share code; you complete the check via the Home Office online service and retain the result with a timestamp.
• Manual document check: For people who hold original acceptable documents from “List A” or “List B” (e.g., a British birth certificate with NI number, or certain immigration status documents). You must see originals in person, verify likeness, check document validity, copy them in a non-alterable format, and note the date.
• Identity Service Provider (IDSP) check for British/Irish passports: You can use a certified provider to complete digital identity verification for British and Irish citizens with a valid passport. Keep the IDVT report.

Note: The temporary COVID-19 “adjusted” checks ended. Unless using an approved IDSP route, you can’t rely on a video call plus a scanned document for your statutory excuse.

Step 2: Check The Documents Are Genuine And Belong To The Candidate

Always confirm the photo matches the person in front of you, names are consistent across documents, and dates make sense. If you’re not sure about a document or there’s an appeal pending, use the Employer Checking Service (ECS) and keep the Positive Verification Notice (PVN) result with your records.

Step 3: Record Keeping And Repeat Checks

To maintain a statutory excuse, you must:

• Keep a clear copy of the RTW evidence (online check result, non-alterable copies of documents, or IDSP output) - securely stored and retrievable.
• Record the date the check was undertaken.
• Schedule and complete follow-up checks before visa expiry for anyone with time-limited permission (List B).

Step 4: Align Contracts And Policies With Your Process

Your Employment Contract should make employment conditional on having - and maintaining - the right to work in the UK, and allow termination if RTW is lost or evidence isn’t provided. That way, your HR process and legal documents work together if you need to act quickly.

Common Pitfalls To Avoid

• Not doing checks before the first day of work.
• Accepting photocopies or screenshots when an original or online check is required.
• Missing repeat check dates for time-limited permissions.
• Applying different standards to different candidates (risking discrimination). More on fair hiring and avoiding illegal interview questions below.

Right To Work Beyond Direct Employees

Your compliance plan should cover all routes into your workforce, not just standard hires. In practice:

• Agency workers: Ensure the agency is contractually responsible for RTW checks and audit rights are built in. A solid Agency Worker Hire arrangement will address who does checks, what evidence is shared, and indemnities if things go wrong.
• Contractors and subcontractors: You still need to manage risk where individuals are embedded in your operations. Clear contractor paperwork helps - for example, a Contractors Agreement that requires valid RTW and permits you to verify it.
• Secondments: If staff are seconded into your business, set expectations for checks and information sharing in your Secondment Agreement.

Agencies, Contractors And Overseas Teams: Who Is Responsible?

Responsibility ultimately follows control. If an individual is working for your business in the UK - even via a third party - the Home Office expects you to ensure the right checks are being done and to act on red flags. Contracts are your friend here: they clarify who checks what, when evidence is shared, and who carries the risk.

For genuinely offshore teams, UK RTW checks won’t apply. But think carefully before “offshoring” roles done by individuals located in the UK. If you’re engaging talent abroad, factor in local employment and tax rules and ensure you’re not inadvertently creating a UK employment relationship. We have a practical overview on managing risk when engaging overseas contractors - helpful if you’re building a hybrid or global team.

Finally, franchisors and prime contractors should carry out periodic audits of franchisees and suppliers. Supply chain clauses that require RTW compliance, evidence on request, and prompt correction of issues are standard risk controls.

What To Do If You Discover An Illegal Worker

Discovering a problem doesn’t mean panic - but you do need a calm, defensible process.

1) Pause And Assess The Evidence

Don’t jump to conclusions based on rumour. Check your RTW records first - if you carried out the correct check and have proof, you may already have a statutory excuse. If evidence suggests the person lacks permission to work, consider whether you need to verify through the Employer Checking Service.

2) Take Proportionate, Fair Interim Steps

If there’s a genuine, serious concern, you can consider a temporary suspension while you investigate. This should be on full pay unless your contract clearly provides otherwise and it’s reasonable in the circumstances. For process pointers, see our guidance on employee suspension rules.

3) Investigate Promptly And Keep Records

Run a fair, well-documented process: set out the concern, give the individual a chance to respond, and record your findings. A structured approach helps you reach the right decision and reduces employment law risk - our step-by-step workplace investigations guide is a helpful overview.

4) Decide The Outcome

Outcomes will vary. If the individual can prove RTW (for example, through a Positive Verification Notice) you may reinstate. If they cannot, dismissal may be justified - but ensure you follow a fair process and rely on contractual clauses that make continued employment conditional on valid RTW. Where appropriate, consider reporting to the Home Office.

5) Learn And Improve

Every incident is a chance to strengthen your compliance. Update your checklists, refresh training, and tighten contracts with agencies or suppliers if gaps appeared.

Records, Data Protection And Fair Hiring

Right to Work processes are only as good as your records and the way you handle them.

How Long Should You Keep Right To Work Records?

Keep RTW evidence for the duration of employment and for at least two years after the employment ends. This aligns with Home Office guidance and gives you proof if a query arises later.

GDPR And Handling Identity Documents

RTW checks inevitably involve personal and special category data (photos, identity details). Under UK GDPR and the Data Protection Act 2018 you must:

• Have a clear lawful basis for processing (legal obligation is common for RTW checks).
• Limit access to those who need it, store securely, and set retention schedules.
• Be transparent with candidates and staff via your Privacy Policy, and be ready to respond to subject access requests.

If you’re building out your privacy compliance, our practical GDPR Package and Privacy Policy are designed for small businesses handling HR and recruitment data.

Avoiding Discrimination And Bias

Right to Work compliance must sit alongside your Equality Act 2010 duties. Apply the same RTW process to all candidates, irrespective of nationality or ethnicity, and don’t ask questions that could be discriminatory. A quick refresher on what’s off-limits during hiring can help your team steer clear of illegal interview questions.

Training And Audits

Give hiring managers simple, up-to-date checklists and short training. Periodically audit a sample of files to ensure documents are complete, readable, dated, and that follow-up check reminders are in place.

Key Takeaways

• “Illegal worker” means someone without permission to do the work in question in the UK; employers must run compliant Right to Work checks to avoid liability.
• Penalties are serious: civil fines up to £60,000 per illegal worker, with potential criminal liability where you know or have reasonable cause to believe someone can’t work.
• Follow the correct check type (online share code, manual, or IDSP), verify documents carefully, and keep dated records; repeat checks are required for time-limited permissions.
• Extend your compliance to agency staff, contractors and secondees through clear contracts, audit rights and indemnities; don’t assume a supplier has it covered.
• If a problem arises, act fairly: review records, consider a paid suspension while you investigate, document the process, and decide outcomes consistently with your contracts and policies.
• Protect data and people: store RTW evidence securely under UK GDPR, apply your process consistently to avoid discrimination, and keep records for employment + 2 years.
• Put your legal foundations in place - strong Employment Contracts, supplier terms for agency workers and contractors, fair process tools for workplace investigations, and privacy documents - so you’re protected from day one.

If you’d like tailored help setting up robust Right to Work processes, drafting employment and supplier terms, or handling a live issue, our team is here to help. You can reach us on 08081347754 or team@sprintlaw.co.uk for a free, no-obligations chat.