By law all employers in the UK, without exception, have to perform right to work checks or face civil penalties.
Employers who carried out the right to work checks correctly have a statutory excuse against liability for a civil penalty if an employee is later found working for them illegally.
The procedure for the right to work checks is specified by the Home Office in their right to work checks guidance. You need to obtain the relevant document(s) from your prospective employee that show the right to work in the UK.
From our experience we can see that many employers do not carry out the right to work at all or do not carry it out correctly. This can have serious consequences including high financial penalties and revocation of sponsor licence. Neglect and mistakes are particularly common when employing a migrant worker in supplementary employment when the migrant is already sponsored by another employer.

Right to work checks and supplementary employment
The Skilled Worker guidance states that a Skilled Worker can undertake supplementary employment if the supplementary employment is in an occupation listed in Tables 1, 2 or 3 of Appendix Skilled Occupations.
Workers on the below listed sponsored routes can undertake supplementary employment that appears in Appendix Immigration Salary List or is in the same profession and at the same professional level as the job for which the certificate of sponsorship (CoS) was assigned:
• the Intra-Company routes in place before 11 April 2022 • Senior or Specialist Worker (but only if they qualify under a transitional arrangement • T2 Minister of Religion • International Sportsperson • Creative Worker • Government Authorised Exchange • International Agreement (but only if the worker has been granted as an employee of an overseas government or international organisation) • Religious Worker Unless an exception applies in the Sponsorship Guidance, the supplementary employment will only be permitted if the sponsored worker continues to work for their sponsor.
Right to work checks mistakes when additional supplementary employment
In any case in which you are offering additional supplementary employment to an eligible sponsored worker, the supplementary employment must not:
• exceed 20 hours per week
• take place during the contracted hours for their sponsored employment In order to obtain a statutory excuse against a civil penalty, you are required to confirm that the worker has the right to work in the UK and is allowed to carry out the work in question.
When carrying out the check, you will need to ensure that the supplementary employment meets the above requirements by, for example, asking the worker to provide a letter or other evidence from the sponsor confirming:
• They’re working for their sponsor • The job description and occupation code of their sponsored employment (for routes other than Skilled Worker whose supplementary employment is not in the Immigration Salary List) • Their contractual working hours
You will no longer have a statutory excuse if, during the course of employment, you become aware that a sponsored worker is working in breach and you continue to employ them in spite of that knowledge.
What employer has to do in line with Home Office guidance
If, at any point during the course of employment, you believe that the sponsored worker may have ceased working for their sponsor, or that their contractual hours have changed, you should request further information to confirm whether they are still eligible to carry out the supplementary employment.
If you identify that the sponsored worker is working in breach, you are required to take the appropriate action. This may include contacting the Home Office for support and/or taking steps to terminate employment.