EXPLOITATION RISKS IN THE UK SKILLED WORKER VISA AND CERTIFICATE OF SPONSORSHIP SYSTEM: A STUDY OF ILLEGAL MIGRATION.

INTRODUCTION

In recent years, there has been a significant increase in the number of Nigerian nationals seeking opportunities to migrate to the United Kingdom for various reasons, most particularly employment and education. Due to the absence of a visa-free travel agreement between Nigeria and the United Kingdom, Nigerian citizens are required to obtain a visa before entry into the UK.

Among the available legal migration pathways, the UK Skilled Worker visa, previously classified as a Tier 2 (General) visa category under the former points-based immigration system, has become one of the most commonly used routes for migration to the UK by foreign nationals. The Health and Care Worker visa, a subset of the Skilled Worker visa, was introduced by the UK Home office in August 2020, to address the shortage of staff within the health and care sector caused by Brexit and Covid. This opened up a major route for migration to the UK, as the government sought to meet growing demands in the health and care sectors through international recruitment.

According to the UK Home Office immigration statistics, about 252,775 work visas (including dependants) were granted across various categories in the year ending March 2026, with Skilled Worker and Health and Care Worker visas forming a significant proportion of these approvals.1 Within the same reporting period, the Skilled Worker route, although in recent decline, accounted for over 110,000 visa grants, demonstrating its continued importance as a primary labour migration channel into the United Kingdom.2

These routes operate within a structured legal framework under the UK Immigration Rules, which requires that applicants must have a genuine job offer from a Home Office-approved sponsor before a Certificate of Sponsorship can be issued. The Certificate of Sponsorship (CoS) is therefore a central requirement for skilled worker visa applications serving as formal confirmation that a migrant has been offered legitimate employment in the United Kingdom.3

However, despite the existence of these legal safeguards, concerns have increasingly emerged regarding the exploitation and misuse of the CoS system. Reports of fraudulent job offers, sham sponsorship arrangements, and non-existent employment opportunities have raised serious questions about the integrity of certain licensed sponsors’ practices and the vulnerability of intending migrants.

This article therefore examines the exploitation risks associated with the UK Skilled Worker visa and Certificate of Sponsorship system, with particular focus on how these vulnerabilities intersect with illegal migration practices. It further analyses the relevant legal framework, patterns of fraudulent conduct, and the consequences under both UK immigration and criminal laws.

UNDERSTANDING LEGAL AND ILLEGAL MIGRATION IN THE UNITED KINGDOM.

To better understand what constitutes legal and illegal migration, we may have to remind ourselves what migration means. In simple terms, migration refers to when people move from one country, region, or place to another, either temporarily or permanently. Migration into any country or region that strictly follows immigration rules and guidance set by such country (in this case the UK), would be classed as Legal Migration. Any act or conduct of migration in contrast to this is illegal migration. It is a structured process governed by statute and policy, managed by the UK Home Office, requiring strict compliance with visa conditions, documentation requirements, and eligibility criteria.4

Illegal migration into the UK would include entry without valid leave to remain (visa), overstaying a visa, or obtaining entry through deception or false representation. Under section 24 of the Immigration Act 1971, it is a criminal offence to enter or remain in the United Kingdom in breach of immigration laws, reinforcing the seriousness of non‑compliance.5

The legal framework governing irregular migration has been further reinforced by the Illegal Migration Act 2023, which forms part of the UK’s broader border enforcement strategy.6 Echoing the provisions of the act, individuals who enter the UK without a valid visa, use false or fraudulent documents during the immigration process, or those who arrive through irregular routes are bound to be subject to immigration enforcement actions.7

Migration from countries such as Nigeria is primarily driven by economic, educational, and family‑related factors. Nigeria remains one of the leading countries of origin for migrants entering the UK labour and education systems. According to the UK’s Office for National Statistics, immigration to the UK continues at high levels, with hundreds of thousands of individuals entering annually through both work and study‑related routes.8

Various legal routes exist to migrate to the UK, one of such is the Skilled worker visa which is our main focus in this article. Other common visa routes and leave to remain available for migration to, or residence in, the UK include, but are not limited to, the EU Settlement Scheme (including pre-settled and settled status), Student visas, Family visas (including applications based on Article 8 of the European Convention on Human Rights), Innovator Founder visas, Global Talent visas, and Visitor visas. 

Each of these immigration routes is governed by stringent eligibility criteria and regulatory requirements. In the case of the Skilled Worker visa, applicants are generally required to secure sponsorship from a licensed employer, meet specified salary and financial thresholds, demonstrate English language proficiency, and comply with the conditions and restrictions attached to their visa status. According to data published by the Office for National Statistics (ONS), Nigerians have consistently ranked among the leading non-EU nationalities migrating to the United Kingdom in recent years, particularly through work and study routes. The UK Home Office Immigration System Statistics confirm that work and study routes remain among the most frequently issued visas, with over 250,000 work visas (with dependents) granted in recent reporting periods.9

Compliance with these requirements is not merely procedural. It is the foundation of lawful residence in the United Kingdom. Where a migrant does not meet these obligations whether by overstaying, breaching visa conditions, or entering without a valid visa, the consequences could be severe. Under UK immigration law, such non‑compliance may result in refusal of entry, cancellation of existing leave, detention pending removal, and restrictions on future visa applications. In cases involving deception or fraud, liability may also arise under the Fraud Act 2006, further compounding the risks faced by migrants who attempt to circumvent lawful procedures.10

Thus, the legal framework underscores a clear principle, migration must occur through authorised routes, with strict adherence to statutory requirements. Any deviation exposes migrants not only to immigration enforcement but also to potential criminal prosecution, making lawful compliance the only sustainable pathway.

THE UK SKILLED WORKER VISA AND CERTIFICATE OF SPONSORSHIP SYSTEM.

The Skilled Worker visa is a central pillar of the United Kingdom’s points‑based immigration system and remains one of the most significant legal routes through which foreign nationals, including Nigerians, migrate for employment purposes. Unlike purely individual applications, this is a sponsor‑led system. Entry into the UK for work depends on a confirmed job offer from an employer authorised by the Home Office to employ migrant workers.11

This route replaced the former Tier 2 (General) visa and is governed by the Immigration Rules, particularly Appendix Skilled Worker.12 It is designed to regulate migrant labour, ensuring that entry is tied to genuine employment needs within the UK economy.

At the centre of this framework lies the Certificate of Sponsorship (CoS), a mandatory requirement for any Skilled Worker visa application. A CoS is not a physical certificate but an electronic record generated by a licensed sponsor through the Home Office’s Sponsorship Management System.13 It contains essential details such as the applicant’s personal information, job role, salary, occupation code, and employer details, serving as official confirmation of a qualifying job offer. 

A CoS may only be issued once the employer has obtained a valid sponsor licence from the Home Office.14 This licence is granted following an assessment of the business’s legitimacy, operational capacity, and ability to comply with sponsorship duties. Once approved, the employer is placed on the Register of Licensed Sponsors,15 which legally permits them to sponsor foreign workers to take up work in the UK.

The process of issuing a CoS commences when a UK employer identifies a genuine vacancy or work needs, that meets the eligibility requirements of the Skilled Worker route. Upon recruitment, following on from Applicants’ interviews and vetting process, the employer assigns a CoS through the Sponsorship Management System, generating a unique reference number used by the migrant in their visa application. A CoS is valid for three months from issuance, and if not used within that period, it expires. Crucially, the issuance of a CoS does not guarantee visa approval, the Home Office retains the power and duty to assess eligibility, genuineness of the job offer, and compliance with immigration rules.

Employers holding sponsor licences are subject to strict compliance obligations. These include maintaining accurate employment records, ensuring sponsored roles are genuine, reporting changes in employment circumstances, and cooperating with Home Office audits.16 Non‑compliance may result in suspension or revocation of the licence, effectively preventing the employer from sponsoring foreign workers.

Applicants themselves must meet eligibility requirements under the points‑based system. This includes a valid CoS, minimum salary thresholds, skill level requirements, and English language proficiency. These criteria ensure that migration is structured and consistent with UK labour market needs.

The Health and Care Worker visa, a subcategory of the Skilled Worker visa, became one of the most popular immigration routes to the UK following its introduction in 2020. The route was designed to address significant workforce shortages within the UK's health and social care sector. However, persistent concerns about exploitation and abuse within the scheme have resulted in stricter regulatory measures, which have in turn contributed to a reduction in the number of Health and Care Worker visas granted in recent years. Media reports, including investigative journalism into the immigration route by the BBC in 2024 and 2025, have highlighted instances of abuse and fraudulent practices, with many migrants reportedly falling victim to scams involving fake job offers and sponsorship arrangements17. In some cases, individuals were allegedly defrauded of sums ranging between £5,000 to £30,000 in exchange for promised employment and visa sponsorship 

Overall, the Skilled Worker visa and Certificate of Sponsorship system balances labour market needs with immigration control. Yet its reliance on employer sponsorship also creates vulnerabilities, particularly where fraudulent sponsorship arrangements or non‑genuine employment offers arise. These risks form the basis of regulatory concern and highlight the potential for exploitation within the system.18

CERTIFICATE OF SPONSORSHIP FRAUD AND EXPLOITATIVE PRACTICES.

The Certificate of Sponsorship (CoS) is issued free of charge to the visa applicant. A prospective migrant using this route is generally required to pay only the applicable visa application fee, the Immigration Health Surcharge (IHS), and any associated travel or relocation costs. The costs of assigning a Certificate of Sponsorship and the Immigration Skills Charge are the responsibility of the sponsoring employer. These costs must not, under any circumstances, be passed on to, recovered from, or charged to the sponsored worker. In many reported, and likely numerous unreported cases, intending and vulnerable migrants have been persuaded to pay substantial sums of money in exchange for a CoS, which is a mandatory requirement for a Skilled Worker visa application. Upon arriving in the UK, some of these workers discover that the promised employment does not exist. In other cases, the Certificate of Sponsorship itself is found to be fraudulent, leaving migrants without lawful employment and often in precarious immigration and financial circumstances.19

A common pattern of exploitation involves situations where an individual in Nigeria is approached by an "agent", recruiter, or purported employer offering a supposedly guaranteed job opportunity in the United Kingdom. The individual is informed that a CoS can be obtained in exchange for a substantial payment and may be assured that accommodation, employment, and settlement arrangements have already been secured.

In some cases, prospective migrants sell personal property, deplete their savings, or borrow significant sums of money to finance the process. However, upon arrival in the UK, they may discover that the sponsoring company has little or no genuine operational presence, that the promised role does not exist, or that the sponsor has become entirely unreachable. In many such arrangements, material facts concerning the true nature of the employment opportunity are deliberately concealed from the migrant throughout the recruitment and migration process.

While the CoS framework was originally designed as a lawful sponsorship mechanism to facilitate genuine employment migration, reports of abuse, deception, and exploitative recruitment practices have increasingly emerged in recent years.20 These schemes often operate through a chain or network of between three and six individuals, each performing a specific role in the fraud. For example, some members may receive payments on behalf of others within the network, while others conduct sham interviews to create the appearance of a legitimate recruitment process and gain the victim's trust. 

Another recurring issue involves the establishment or use of sham companies solely for immigration sponsorship purposes. In some situations, individuals or entities obtain sponsor licences from the UK Home Office under the appearance of legitimate business activity, only to use such licences to assign a CoS for non-existent or inactive job roles. These companies may have irregular or no genuine operational presence and exist primarily as vehicles for immigration-related deception. Such practices undermine the integrity of the sponsorship system and expose migrants to significant legal and financial risks.

False job offers remain a significant feature of exploitative sponsorship arrangements. Prospective migrants are often promised employment opportunities with attractive salaries that meet the Home Office's salary thresholds, together with favourable working conditions and career prospects. However, upon arrival in the UK, many discover that these representations were misleading or entirely false.

The exploitation arising from these arrangements often extends beyond immigration deception alone. Migrants who arrive in the UK under false sponsorship arrangements face financial hardship, homelessness, irregular immigration status, inability to secure lawful employment, and vulnerability to further exploitation. Many victims are reluctant to report these situations due to fear of immigration consequences or deportation.

These practices may amount to fraud under the provisions of the Fraud Act 2006. In particular, section 2 creates the offence of fraud by false representation, which occurs where a person dishonestly makes a false representation with the intention of making a gain for themselves or another, or causing loss to another or exposing another to a risk of loss.21 This has become a norm within the Skilled worker visa route and the CoS structure. 

Similarly, Section 3 establishes the offence of fraud by failing to disclose information where a person dishonestly fails to disclose material information which they are under a legal duty or expectation to disclose.22 In the context of sponsorship arrangements, this may occur where an employer, recruiter, or intermediary intentionally conceals material facts from a migrant, including the lack of a genuine vacancy or the fact that the sponsoring organisation is inactive, non-operational, or unable to fulfil its sponsorship obligations. Such omissions may induce the migrant to proceed with the arrangement on the basis of a false understanding of the circumstances resulting in dire immigration and financial decisions. 

Common warning signs associated with fraudulent sponsorship arrangements include:

• demands for payment before issuance of a CoS;
• absence of formal interviews or recruitment procedures;
• refusal to provide sponsor licence details;
• unverifiable company addresses or online presence;
• unrealistic salary promises; and
• pressure to make urgent financial commitments.

These indicators do not automatically establish fraud, but they frequently appear in cases involving non-genuine sponsorship arrangements and immigration deception.

The increasing prevalence of Certificate of Sponsorship fraud demonstrates the vulnerabilities that may arise within employer-sponsored migration systems where oversight, desperation for migration opportunities, and financial exploitation intersect. It further highlights the importance of due diligence, regulatory enforcement, and access to proper legal guidance for intending migrants navigating the UK immigration process.

LEGAL CONSEQUENCES AND SANCTIONS UNDER UK LAW

The legal consequences arising from fraudulent CoS arrangements and immigration deception within the United Kingdom are often severe and far-reaching. Under UK immigration and criminal laws, both migrants and sponsors may face significant sanctions where immigration rules are breached, false representations are made, or sponsorship systems are abused. The UK immigration framework places considerable emphasis on compliance, genuineness of employment, and the integrity of the sponsorship process, particularly under the Skilled Worker route.

One of the most immediate consequences of non-compliance is visa refusal or cancellation. Where the UK Home Office determines that a CoS was obtained through deception, linked to a non-genuine vacancy, or connected to fraudulent sponsorship arrangements, a Skilled Worker visa application may be refused outright.23 In circumstances where the visa has already been granted, the Home Office retains the power to curtail or cancel leave to remain upon discovery of non-compliance, deception, or breach of immigration conditions.24

Beyond visa refusal, individuals who enter or remain in the UK through fraudulent sponsorship arrangements may also become subject to immigration enforcement action, including detention, removal, deportation, and re-entry restrictions. The Illegal Migration Act 2023 further strengthens the UK government’s approach toward illegal migration by reinforcing removal powers in circumstances involving unlawful entry or non-compliance with immigration control requirements.25

In addition to immigration sanctions, criminal liability may arise where fraudulent conduct is established under the Fraud Act 2006.26 The Proceeds of Crime Act 2002 (POCA) may also be relevant in circumstances where employers or intermediaries obtain money from prospective migrants as a result of fraudulent conduct. Any financial benefit derived from such activities may constitute criminal property under POCA, thereby exposing those involved to further criminal and civil recovery proceedings in addition to liability for the underlying fraud.27 Employers found to have engaged in sponsorship abuse or immigration non-compliance may face suspension or revocation of their sponsor licences by the UK Home Office.28 Sponsor licence revocation carries significant implications, as it immediately prevents the employer from assigning new Certificates of Sponsorship and may affect existing sponsored workers connected to the organisation. The Home Office also possesses powers to conduct compliance inspections, document reviews, and enforcement visits to ensure that licensed sponsors continue to satisfy their regulatory obligations.

Recent enforcement trends demonstrate increasing scrutiny of sponsorship compliance within the UK. In 2023 and 2024, the UK Home Office reportedly revoked hundreds of sponsor licences across sectors including healthcare and social care following concerns relating to non-genuine vacancies, exploitation risks, and breaches of sponsorship duties.29 These developments reflect growing regulatory concern regarding abuse of the Skilled Worker and Health and Care Worker visa routes.

Nevertheless, an important distinction must be drawn between migrants who knowingly participate in fraudulent arrangements and those who were genuinely deceived. In certain circumstances, individuals who can demonstrate that they acted in good faith, reasonably relied on representations made by sponsors or agents, and were unaware of the fraudulent nature of the arrangement may receive different consideration from immigration authorities depending on the facts of the case. Although such circumstances do not automatically exempt a person from immigration consequences, the existence of genuine deception may become relevant during immigration reviews, appeals, or enforcement assessments. This distinction is particularly important because many intending migrants are unfamiliar with the technical operation of the UK sponsorship system and may rely heavily on representations made by employers, recruiters, or intermediaries.

IDENTIFYING GENUINE UK JOB OFFERS AND AVOIDING CoS SCAMS.

Given the increasing prevalence of fraudulent sponsorship arrangements within the UK immigration system, intending migrants must exercise caution before accepting employment offers or commencing relocation processes. Many migrants become victims of CoS scams because they fail to properly verify the legitimacy of sponsors, recruiters, or employment arrangements before making financial commitments.

One of the most important safeguards available to intending migrants is the verification of licensed sponsors through official UK government channels. Only employers approved and licensed by the Home Office are authorised to sponsor foreign nationals under the Skilled Worker route.30 The UK government also maintains an official Register of Licensed Sponsors through the GOV.UK website, allowing migrants to verify whether an employer is legally recognised by the Home Office.31

Before proceeding with any sponsorship arrangement, migrants should confirm that:

• the employer appears on the official sponsor register;
• the company has a genuine operational presence in the United Kingdom;
• the job role corresponds with the sponsorship category; and
• proper employment documentation has been provided.

Particular caution should also be exercised when dealing with informal agents or intermediaries operating through social media or unverified referral systems. Failure to conduct proper due diligence may expose intending migrants to significant financial and immigration risks.

CONCLUSION AND RECOMMENDATIONS.

The United Kingdom Skilled Worker visa route remains a legitimate pathway for lawful migration and employment opportunities. However, the increasing rise of Certificate of Sponsorship fraud and exploitative sponsorship arrangements has exposed many intending migrants, particularly Nigerians, to serious financial, legal, and immigration risks.

As discussed throughout this article, many of these challenges arise from false job offers, fake sponsorship arrangements, lack of proper verification, and reliance on unregulated agents or intermediaries. The consequences often extend beyond financial loss and may result in visa refusal, immigration sanctions, or exposure to exploitative conditions in the UK.

It therefore becomes increasingly important for intending migrants to properly understand how the UK sponsorship system operates, verify employers through official government channels, and avoid informal or undocumented recruitment arrangements. Migration decisions should be approached with caution, proper due diligence, and adequate legal awareness.

Safe and lawful migration can only be achieved where individuals are properly informed and guided throughout the immigration process. Intending migrants are therefore strongly encouraged to seek guidance from qualified immigration lawyers or regulated immigration advisers before making any significant immigration or financial commitments.