Jacqueline Moore

Jacqueline Moore, partner and head of immigration at Thorntons said businesses that believe they are complying with immigration law could still be exposed to substantial penalties if their procedures do not meet the Home Office’s requirements.

The advice comes as official figures show a marked increase in enforcement against illegal working, such as recent raids in Fraserburgh and Mallaig.

Immigration Enforcement carried out 7,270 visits across the UK between January and June 2026, a 31 per cent increase on the same period in 2025. Those visits resulted in 4,756 arrests.

More than 1,200 businesses were issued with civil penalties during the six-month period, with potential fines totalling more than £74 million.

The Home Office says almost 25,000 visits took place in the two years to the end of June 2026, 111 per cent more than during the preceding two years.

The risks for businesses will change again on 1 October when section 48 of the Border Security, Asylum and Immigration Act 2025 comes into effect.

The legislation extends UK right-to-work requirements beyond traditional employees to include many other individuals providing services, such as self-employed subcontractors and people engaged through online platforms.

It also introduces “extended liability” provisions which mean that, in certain contractual arrangements, a business could potentially face liability even though it does not have the direct contractual relationship with the individual carrying out the work, such as construction companies who work with subcontractors on building projects.

Ms Moore said: “The figures show very clearly that Home Office enforcement activity is increasing. Businesses should not assume this is an issue confined to employers deliberately breaking the rules.

“We have seen first-hand how an employer acting in good faith can make what appears to be a relatively small mistake and face a very substantial penalty as a result.

“The changes coming on 1 October make this more important because businesses need to think beyond the people they would traditionally regard as their employees. Depending on how they operate, workers, individual subcontractors and other people providing services could now come within the regime.

“For some businesses, the question therefore is about more than whether their existing right to work checks are being carried out correctly. They need to understand who they will be responsible for checking under the new rules and whether their contracts and processes give them the protection they think they need under the new regime.

“That has further implications for procurement, contracting, recruitment and basic risk management in businesses.”

Businesses can establish a statutory excuse against civil penalty liability by carrying out the prescribed right to work checks correctly. From October, businesses potentially affected by extended liability will also need to comply with requirements relating to the relevant contractual arrangements.

Civil penalties can reach £60,000 for each illegal worker. More serious cases can result in criminal prosecution, while other consequences can include loss of the ability to sponsor migrant workers and, in some sectors, licensing implications.

Thorntons is advising businesses to use the period before 1 October to map their workforce and wider working arrangements, review relevant commercial contracts and make sure staff responsible for recruitment and compliance understand the new requirements.