Preventing illegal working & the consequences of employing illegal workers
Illegal working often results in abusive and exploitative behaviour, the mistreatment of illegal migrant workers, tax evasion and illegal housing conditions. It can undercut legitimate businesses and have an adverse impact on the employment of people who are in the UK lawfully. Undocumented workers have also been reported to be an invisible public health risk during the pandemic.

Complied by Judit Adorjan
What can be considered illegal working?
Section 15 of the Immigration, Asylum and Nationality Act 2006 contains the illegal working provisions. Under these provisions, the Secretary of State may serve an employer with a civil penalty notice where they employ a person who is:
Subject to immigration control
Aged over 16
Not permitted to work due to:
- Not having been granted leave to enter or remain in the UK or
- Their leave to enter or remain in the UK is invalid or ceased to have effect by reason of curtailment, revocation, cancellation, passage of time or otherwise. Or they are subject to a condition preventing them from accepting the employment.
Who is responsible for immigration control?
Immigration, Asylum and Nationality Act 2006 shifted the onus for immigration control from the state to private citizens and public servants, such as employers, landlords, GPs, bank tellers.
All employers, not just licensed sponsors, must conduct right to work checks to ensure their employees are entitled to work for them. Ignorance of the law is no defence for employers found non-compliant with their legal obligations.
Who can be defined as an employer?
An employer is someone who engages another person in a contract of employment (a contract of service or apprenticeship) whether express or implied and whether oral or in writing.
Under the Immigration, Asylum and Nationality Act 2006 an employer is not liable for:
- The employees of a contractor
- A genuine self-employed person or freelancer
- Workers from an employment agency who continue to be employees of that agency
Migrate UK has extensive experience working with businesses ensuring adherence to compliance responsibilities. Contact us for free initial advice: 01235 841 568

Karen Kaur and Jonathan Beech
How to prevent illegal working
Employers must check their employees have the right to work in the UK and make sure their documents are valid.
Right to work checks can be conducted manually or online if the employee/prospective employee has an immigration status that can be checked online.
When conducting a manual right to work check, normally the employer must:
- Obtain original versions of one/more of the acceptable documents, such as a current passport, biometric residence permit, a permanent residence card
- Check the documents in the presence of the holder of the documents, and
- Make copies of the documents, retain copies and a record of the date on which the check is made.
Right to work checks have been temporarily adjusted due to COVID-19:
- Checks can now be carried out over video calls
- Job applicants and existing workers can send scanned documents or photos of documents for checks using email or a mobile app
- Employers should record the date they made the check and mark it as “adjusted check undertaken due to COVID-19”
- Employers should use the Employer Checking Service if none of the accepted documents can be provided
Follow-up checks are required for those whose right to work is time limited.
What are the consequences of employing illegal workers?
Compliance officers can refer cases of illegal working for prosecution or the issue of a civil penalty.
You can be sent to jail for 5 years and pay unlimited fine if you are found guilty of employing someone who you knew or had ‘reasonable cause to believe’ did not have the right to work in the UK.
You may be issued with a civil penalty for employing illegal workers if you did not carry out the correct checks, or you did not do them correctly. If this happens you will get a ‘referral notice’ to let you know your case is being considered and you may have to pay a fine of up to £20,000 per illegal worker.
If you are an employer who holds a sponsor licence and you are found liable, your licence may be suspended, and any new licence application may be refused. The Home Office reserves the right to suspend your licence or remove your Certification of Sponsorship (CoS) allocation while any investigation is in progress.
Your business’s details may be published by Immigration Enforcement as a warning to other businesses not to employ illegal workers.
If you are an employer who is subject to immigration control, liability for a civil penalty may be taken into account when considering any future immigration application that you make.
How are civil penalties calculated?
If the employer has not been found to have been employing illegal workers in the past three years, the starting point is £15,000 per illegal worker. For second offences the starting point is £20,000.
You can qualify for reductions by providing evidence that you have met the mitigating factors.
If the employer self-reported the illegal working the penalty will be decreased by £5,000. If they have actively co-operated with the Home Office a further £5,000 will be taken off per illegal worker.
If the employer self-reported the illegal working, actively co-operated with the Home Office and provided evidence of effective right to work checking practices then they might get off with a warning notice instead of being issued a civil penalty.
If a penalty is issued fast payment will result in a further 30% reduction. The final amount will fall between £3,500 and £15,000 per illegal worker. For small businesses this is still an eye-watering amount.
Between 1 July 2019 and 30 September 2019, 574 penalties were issued across the UK, for the value of £10,590,000.
According to the Home Office the purpose of penalties is ‘to encourage employers to comply with their legal obligations’. However, the majority of businesses are unaware of this regime and their duties as there is no publicity surrounding it.
Migrate UK has extensive experience working with businesses ensuring adherence to compliance responsibilities. Contact us for free initial advice: 01235 841 568 or email info@migrate-uk.com

Migrate UK immigration lawyers