The Statutory Excuse: How UK Employers Create and Lose Their Defence Against Illegal Working Fines

What Is the Statutory Excuse and Why Does It Matter?

Under section 15 of the Immigration, Asylum and Nationality Act 2006, it is unlawful for an employer to employ a person who does not have the right to work in the UK. Employers who do so face a civil penalty of up to £60,000 per illegal worker. However, section 17 of the same Act provides that an employer has a complete defence against the civil penalty, the statutory excuse where the employer conducted a prescribed right-to-work check before the employment began and the check did not reveal that the employee lacked the right to work.

The statutory excuse is not automatic. It must be actively created through a compliant check. An employer who employs an illegal worker but conducted a properly compliant check before employment will not be liable for the civil penalty. An employer who did not conduct a check, or whose check was deficient, has no defence.

Criminal Liability: A Separate and More Serious Risk

In addition to the civil penalty framework, section 21 of the 2006 Act creates a criminal offence of knowingly employing an illegal worker. This carries an unlimited fine and up to five years' imprisonment for individuals. The statutory excuse does not protect against criminal liability, an employer who knew or had reasonable cause to believe that a worker did not have the right to work cannot rely on the statutory excuse even if a check was conducted.

Method 1: Manual Document Check

The manual check involves physically inspecting original documents from one of two lists published by the Home Office, List A (workers with a permanent right to work in the UK) and List B (workers with a time-limited right to work).

List A: Documents Providing a Permanent Statutory Excuse

Checking a List A document creates a permanent statutory excuse for as long as the employment continues. No follow-up check is required. List A documents include: a UK passport (or UK and islands passport); a current biometric residence permit (BRP) or UK Visas and Immigration eVisa confirming permanent right to work; a current passport or travel document showing the holder is an EEA national, together with their current BRP or EUSS status; a full birth or adoption certificate issued in the UK, together with an official document showing the holder's National Insurance number; and certain other specified documents.

List B: Documents Providing a Time-Limited Statutory Excuse

A List B check creates a statutory excuse only until the document expires or, in the case of a visa holder, until 12 months after the check was conducted, whichever is sooner. A follow-up check must be conducted at that point. List B documents include: a current passport or travel document showing a time-limited right to work; a current BRP confirming time-limited leave to remain; and certain other specified documents.

The Conduct of the Manual Check: What Must Be Done

The check must be conducted in the physical presence of the document holder (or via a live video link for remote starters). The employer must: obtain the original document; check that it is genuine, has not been tampered with, and relates to the person presenting it; retain a copy (in a secure format that allows the content to be read but cannot be altered); and record the date of the check.

Method 2: Online Share Code Check

For workers who have a right to work recorded in the Home Office's systems, including those with a biometric residence permit, an eVisa, or a UKVI status, the employer can conduct an online right-to-work check through the Home Office's Employer Checking Service at www.gov.uk/prove-right-to-work.

How the Share Code Check Works

The worker generates a nine-character share code through the UKVI online service. The employer enters the share code and the worker's date of birth on the checking service. The system displays the worker's right-to-work status, including any time limitation. The employer must retain a screenshot or digital record of the result, together with the date of the check.

When the Online Check Is Mandatory

Since April 2022, eVisa holders and those who have enrolled their biometric data with the Home Office are no longer issued physical BRP cards for new applications. These workers do not hold a physical document to present for a manual check — the online share code check is the only valid method for verifying their right to work.

Method 3: IDSP Digital Identity Check for British and Irish Nationals

British and Irish citizens can have their right to work verified through a certified Identity Service Provider (IDSP). This is a digital identity check that verifies the individual's identity and confirms their right to work without the need to inspect a physical document.

Who Can Use IDSP Checks

IDSP checks are available for British and Irish citizens only. They cannot be used for workers who are non-British/Irish EEA nationals or for visa holders, those groups must use the manual check (for those with physical documents) or the online share code check.

Employer Responsibility

The employer remains responsible for ensuring the IDSP they use is certified by the UK government's Digital Identity and Attributes Trust Framework. Using an uncertified IDSP does not create the statutory excuse. A list of certified IDSPs is published by the government. 

What Creates the Statutory Excuse: The Timing and Record-Keeping Rules

The statutory excuse is created only where: (1) the check was conducted before employment commenced; (2) the correct check method was used for that type of worker; (3) the check was thorough, the document was inspected in the presence of the holder, checked for authenticity, and the content verified; and (4) a copy was retained in the correct format with the date of the check recorded.

What Destroys the Statutory Excuse: Common Employer Mistakes

Check conducted after employment start: The most common and most costly mistake. No statutory excuse is created for any period of employment before the check.

Accepting a document not on List A or B: Only documents on the Home Office's prescribed lists create the statutory excuse. Accepting a driving licence alone, for example, does not.

Copy not retained: A copy of the document or online check result must be retained securely. Failure to retain it means the employer cannot evidence the statutory excuse.

Check not repeated for List B workers: Where a worker's right to work is time-limited, the employer must conduct a follow-up check before the earlier of: the document's expiry date, or 12 months after the original check.

IDSP provider not certified: Using an uncertified IDSP does not create the statutory excuse.

Share code check result not retained: The screenshot or record of the online check must be retained with the date.

Frequently Asked Questions

Does conducting a right-to-work check guarantee no penalty if an illegal worker is employed?

Yes, a compliant statutory check creates a complete defence against the civil penalty, even if the worker subsequently turns out to have no right to work. The defence only fails if the employer knew or had reasonable cause to believe the worker lacked the right to work despite the check.

What if a worker's visa expires during employment?

Where a worker's leave expires, their right to work ceases. The employer must not continue to employ them beyond the expiry of their leave unless a new visa has been granted or an in-time application has been made (in which case the Employer Checking Service should be used to verify the worker's continued right to work under Section 3C leave).

How long must right-to-work records be retained?

Records must be retained for the duration of the employment and for two years after the employment ends. Records should be stored securely and should be producible within a reasonable time if the Home Office requests them during a compliance visit.