In late 2025, research from the Credit Industry Fraud Avoidance System (Cifas) revealed that 1 in 5 employees had, during their careers, secretly held two competing roles at the same time.
Earlier this year, a Croydon Council housing official was convicted of fraud, given a 12-month suspended jail sentence and fined £10,000 after it was found that she had been working a second full time job at another London authority for two years.
This practice, known as ‘moonlighting’, or ‘polygamous working’, involves individuals taking on other (sometimes multiple) full-time roles outside of their primary employment, and often without their employer’s knowledge.
Moonlighting has become increasingly prevalent in recent years, driven by economic pressures, such as rising living costs, alongside the expansion of remote and hybrid working. Greater flexibility of working has enabled employees to more easily take on numerous different roles concurrently, blurring the boundaries between employers.
Cifas also found that 24% of employees considered it ‘justifiable’ to work in this way, including in respect of competing roles, reflecting a growing tolerance towards the practice. However, this presents significant challenges for employers.
Risks of moonlighting
The rise of moonlighting introduces an array of legal, wellbeing, performance, and operational risks. These include potential conflicts of interest, breaches of confidentiality, misuse of confidential information, decline in productivity, and employee burnout.
The issue is especially acute in the technology sector, where fully-remote working is the widespread norm, and tasks are often highly automated, making it easier for individuals to manage several roles simultaneously without detection. So called “mouse jigglers” which keep a mouse moving and can avoid lack of use indications to an employer’s systems that the employee is not working, are apparently now easily available for misuse.
Is moonlighting illegal?
It is not inherently unlawful for an employee to take on a second job, provided that the additional work does not place them in competition with their primary employer, or otherwise harm the primary employer’s legitimate business interests or encroach on their normal working time (if full time, for example). However, moonlighting may well give rise to breach of an employee’s contract of employment, where it is expressly prohibited by contractual terms or they have warranted to provide their employer with their “full care and attention during working hours”. Such conduct may also breach the implied duty of trust and confidence in an employment relationship. Depending on the precise nature of the conduct and contractual terms binding the individual, moonlighting may amount to gross misconduct, and also potentially fraud.
Moonlighting also raises issues under the Working Time Regulations 1998 and the Health and Safety at Work Act 1974. Employers are under a statutory obligation to take all reasonable steps to protect workers’ health and safety, to ensure compliance with statutory working time limits. Time spent working, irrespective of whether for the same employer, will count towards an employee’s working time, leaving employers open to legal risk where limits are exceeded – even if they were unaware of this.
Beyond legal compliance, there are also practical implications. Secondary employment can give rise to performance issues, particularly where competing commitments begin to affect employee productivity, responsiveness and delivery.
Managing and mitigating the risks
Addressing the risks associated with moonlighting requires employers to take a proactive, rather than reactive approach.
In particular, where employees will have access to highly confidential or commercially sensitive information that could be of use to a competitor, employers should consider including express provisions restricting secondary employment in contracts of employment. These provisions are commonly referred to as ‘exclusive service’ clauses and can either prohibit an employee from providing services to another employer altogether, or restrict this without the prior written consent of the main employer. These kinds of provisions will provide clarity on expectations and help mitigate the risk of conflicts of interest, misuse of confidential information and breaches of duty. Any breaches of these contractual terms can then (and should) be viewed as misconduct and investigated according to internal disciplinary processes.
If you have suspicions that a worker is working multiple jobs, you may want to approach this with them. To discharge your duty to take all reasonable steps, you should ask the individual to confirm if they work for anyone else, unless their existing contract already prohibits this. If this is confirmed, you should then consider asking the employee to sign an opt-out agreement if the total time worked exceeds 48 hours a week. If the employee refuses to sign this agreement, then they will need to consider reducing their hours (with you or their alternate employer) to comply with the legal limits.
It is important to note that careful consideration will be required for part time or junior employees where a second job is less likely to cause harm to the business. Moreover, exclusivity clauses in zero hours contracts are unenforceable, as these workers should remain free to undertake other work insofar as possible.
For further advice on this topic, or any other employment issue, please contact a member of our WS Employment team at: employment@wslaw.co.uk.