Prevention of Illegal Working Analysis

United Kingdom

The Asylum and Immigration Act 1996 introduced the original offence of employing someone without permission to work in the UK and the requirement for employers to undertake documentary checks prior to commencement of employment. 10 years later, the Immigration, Asylum and Nationality Act 2006 (effective 29 February 2008) has further strengthened the documentary check requirement.

The Border and Immigration Agency (“BIA”) has published a list of specified documents, which will either alone or in specific combination provide the employer with an excuse against liability. These should be referred to for every employee. Certain prospective employees will be able to provide a document to show they are not subject to immigration control (for example a British or EEA passport). If an employer has sight of the original document, checks it and takes a copy of the passport front cover and details pages, he will have established an excuse for the duration of the employee’s employment. They will not need to be checked again during their employment.

However for other prospective employees on time limited visas, while the same steps have to be followed, post 29 February 2008, their documents will only provide a statutory excuse for 12 months, and they will need to be checked again annually to ensure that validity continues.

Employers should be aware that some documents do not provide any excuse including some letters from the BIA, national insurance numbers, driving licences and other official documents (these are listed in the guidance notes) - it is therefore imperative that employers check the list on each occasion. The BIA has introduced an employer checking service that will help employers to verify any entitlement to work.

Two populations

All employers will now need to data manage their employee population to comply with two varying illegal working regimes. Employees who joined between 29 January 1997 and 29 February 2008 (the first population) should have been subject to documentary checks on recruitment - this statutory excuse will be retained for the duration of their employment.

Employees joining from 29 February 2008 (the second population) will require a check at the beginning of employment and if they have a restriction on the length of time they can be in the UK, will have to be checked every 12 months thereafter until they can provide a document which makes it clear there is no time limit on their stay in the UK e.g. a residence permit conferring indefinite leave to remain or a British passport Employers should therefore have clear records of these two populations, and take the opportunity now to audit the population between 27 January 1997 and 28 February 2008 for whom adequate documentary checks may not have taken place at the requisite time. Employers should also ensure stringent policies are in place to monitor any new starters post 29 February 2008 and where necessary on an annual basis. However, employer policies must avoid racial discrimination - any policy must be applied consistently to all new starters, and not apply solely to those in minority ethnic groups or those are considered “foreign”.

Higher sanctions

The Home Office has introduced a framework for assessment of the level of civil penalty for illegal working, with the maximum fine per illegal employee increased to £10,000. The amount of the fine will vary according to the number of occasions on which a warning/penalty has been issued to an employer. Due to the size of the workforce, the larger the employer, the more likely that penalties have been issued in the past and the greater the risk of higher penalties for any further breaches. However, the framework will also assess whether full, partial or no documentary checks have taken place, giving a clear incentive for employers to review their HR procedures in this area.

S21 of the Act introduces the criminal offence of knowingly employing an illegal migrant. This offence can be committed not only by recruiting someone knowing they do not have permission to work in the UK but also if their leave has expired or been cancelled. In practice this means that should an officer of a company ever come to know of an employee’s illegality, they may be committing a criminal offence punishable by imprisonment for up to 2 years and an unlimited fine if they do not actively seek to address it. The employer will be treated as knowing a fact about an employee if a person within the organisation who has responsibility for an aspect of the employment knows about it. Therefore an employer could be punished for the negligence of an HR advisor. Illegal workers themselves will be prosecuted and potentially removed from the UK.


The BIA guidance states that employers who acquire staff as a result of a Transfer of Undertakings (Protection of Employment) transfer are provided with a grace period of 28 days to undertake the appropriate document checks following the date of transfer. This does not mean that there is a legal obligation on the transferee to do its own checks. The transferee can rely on the transferor’s checks - but if these have been inadequate the transferee will be responsible (subject to any commercial indemnities etc). The grace period means that if a transferee does its own checks, within 28 days of the transfer, and it discovers that any of the transferred staff are working illegally, the transferee will be let off any civil penalty, provided it deals with the relevant illegal workers appropriately. We wonder whether this is a correct application, given the peculiar legal effect of a TUPE transfer.


These reforms give employers a clear incentive to “get their house in order”. We would advise that the following steps are taken:

  • Ensure that you have clear policies in place for checking the status of all employees and include provisions to prohibit anyone starting work for you who has not provided you with the necessary documents;
  • Audit your existing population to ensure documentary check did take place and that your records are complete and up to date;
  • Check whether you have data management systems in place to track all post 29 February joiners with limited leave to remain;
  • HR professionals responsible for undertaking these checks should be offered clear internal policy guidance and full training on their duties.

Should strategic advice or training be required, please contact the immigration team at CMS Cameron McKenna.

For full text of the Prevention of Illegal Working, Immigration, Asylum and Nationality Act 2006 Summary Guidance for Employers, as issued by the Border and Immigration Agency, please click here.