The Dangers Of Polygamous Working For UK Employers

The rise of remote working has brought greater flexibility and autonomy for many employees. At the same time, it has changed how visible work is to employers. For some businesses, that shift has revealed an uncomfortable reality. Employees are quietly taking on more than one job at the same time, sometimes without saying anything at all. What was once the occasional instance of moonlighting has, in some cases, become full-time employment running in parallel with another full-time role.

Polygamous working, sometimes referred to as polyworking, is not inherently problematic. Many people legitimately balance portfolio careers, consultancy work or side businesses alongside employment. Difficulties arise, however, where secondary work is undisclosed, incompatible, or directly conflicts with an employee’s primary obligations. In those circumstances, the risks are not abstract. They are legal, commercial and often reputational.

From an employer’s perspective, the issue is rarely the existence of a second role in itself. The real concern is whether that role undermines contractual duties, compromises confidentiality, or affects performance in ways that are difficult to identify until damage has already been done. Remote working has made that overlap easier to conceal, particularly where performance is measured by outputs rather than time spent.

Confidentiality and conflicts of interest

The most immediate risk associated with polygamous working is confidentiality. An employee who is also working for a competitor, a client, or a business operating in a similar sector may not intend to act dishonestly or cause harm. Even so, the boundaries between roles can blur. Shared knowledge, informal conversations and overlapping commercial insight can all lead to the gradual erosion of confidentiality.

Employment contracts typically include express confidentiality clauses, supported by implied duties of fidelity. In principle, those protections should offer reassurance. In practice, they are often tested too late. By the time an employer discovers that an employee has been working polygamously for a rival business, sensitive information may already have been exposed. Proving what was disclosed, when it occurred, and whether it caused measurable damage can be extremely difficult.

Conflicts of interest do not require a direct competitor to be involved. An employee advising clients in a similar market, or running a business that overlaps with their employer’s services, may find their judgment divided. That divided loyalty alone can be enough to breach the duty of good faith, even where no confidential information has been deliberately shared.

Breach of contract and implied duties

Most employment contracts contain provisions requiring employees to devote their full working time and attention to their role, or to seek consent before taking on additional work. Even where such clauses are absent, employees remain subject to implied duties of fidelity, trust and confidence, particularly during working hours.

In reality, breaches linked to polygamous working rarely present themselves neatly. They tend to emerge gradually, through reduced availability, missed deadlines or a general decline in engagement. By the time the underlying cause becomes clear, the issue is often no longer limited to a technical breach of contract. Trust has usually eroded, and the employment relationship may already be strained.

An employee who works another job during contracted hours is not providing the service they were employed to give. Where the secondary role conflicts with the employer’s business, the breach may extend beyond working time altogether. What makes these situations especially difficult is that they often come to light only after performance concerns have been raised or disclosures are made inadvertently.

Working time, fatigue and an employer’s duty of care

Polygamous working also brings working time limits and health and safety obligations into sharper focus. On paper, an employee’s contracted hours may appear compliant. In reality, those hours may represent only part of a much larger working week.

Under the Working Time Regulations 1998, workers must not work more than an average of 48 hours per week, calculated over a rolling reference period, unless they have signed a valid opt-out agreement. They are also entitled to a minimum daily rest period of 11 consecutive hours in each 24-hour period, rest breaks during the working day where applicable, and at least one full day off each week or two days off in a fortnight.

Where an employee is working two jobs simultaneously, those hours accumulate. An employer cannot assume compliance simply because the hours contracted with them fall within statutory limits. If the combined total exceeds the 48-hour average, or if rest periods are consistently compromised, there is a real risk of breach. That risk does not necessarily disappear because neither employer was fully aware of the other role.

Employers also owe a wider duty of care to protect the health and welfare of their employees so far as is reasonably practicable. Fatigue is a recognised workplace risk. Where an employee appears persistently overtired, makes uncharacteristic mistakes or struggles to concentrate, the issue may be less about why those hours are being worked and more about whether warning signs were missed.

If polygamous working contributes to illness, stress or a serious error, employers may later face difficult questions about whether concerns should have been explored sooner. The fact that excessive working hours were self-imposed does not automatically remove responsibility, particularly where indicators were visible but overlooked.

Performance management and workplace trust

Undisclosed secondary employment can distort how performance is assessed and managed. An employee dividing their time between roles will often struggle to maintain the same level of focus and availability. Without knowing the real reason, managers may treat this as a capability issue and begin formal performance processes based on incomplete information.

This can place employers in a difficult position. Decisions are taken, warnings are issued, and relationships deteriorate, all before the underlying cause is properly understood. When it later emerges that the employee was working elsewhere, the issue often shifts abruptly from performance to trust, with little room left for repair.

The impact is rarely confined to the individual concerned. Colleagues may have absorbed additional work without explanation. Resentment can build quietly. Once polygamous working comes to light, perceptions of fairness and transparency within a team can change very quickly.

The enforcement problem

Even where employers suspect polygamous working, proving it is rarely straightforward. Investigating too aggressively risks breaching privacy, data protection obligations or the implied duty of trust and confidence. Doing nothing, however, leaves the business exposed.

Monitoring employees’ activity outside working hours is fraught with legal risk. Scrutinising social media, tracking devices or drawing conclusions from limited evidence can easily backfire. Legitimate concern does not give employers free rein to intrude into private life. The way evidence is gathered matters as much as the conclusions drawn.

This is where contractual clarity becomes critical. Where employees are required to disclose secondary employment or seek approval in advance, employers are entitled to ask direct questions and expect honest answers. Without those foundations, enforcement becomes far more uncertain.

Getting ahead of the issue

The most effective way to manage polygamous working is not through reactive enforcement, but through clarity. Contracts should reflect modern working practices and set out expectations around secondary employment in clear terms. Policies on remote and flexible working should address availability and responsiveness explicitly, rather than relying on assumption.

Employers should also be prepared to ask the question directly, both at recruitment stage and during employment. Many assume employees will volunteer information about additional work. In practice, unless disclosure is clearly required, it often does not happen.

Where polygamous working is identified, responses should be proportionate. Not every case warrants dismissal. Much will depend on whether there has been dishonesty, whether confidentiality has been compromised, and whether the business has suffered harm. A measured response, informed by legal advice, is far more likely to protect the employer’s position than a reflexive one.

A question of clarity, not conduct alone

Polygamous working reflects a broader shift in how people approach employment. Remote working has made it easier to layer commitments in ways that would have been difficult a decade ago. Treating the issue purely as misconduct risks missing the underlying cause.

For employers, the real question is whether expectations were clear, safeguards were in place, and warning signs were recognised early enough. Those who address the issue thoughtfully, by reviewing contracts, training managers and encouraging transparency, are far better placed to manage the risks when they arise.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.