More than one-third of employees (36%) have a side job in the gig economy, according to a new survey from Clutch, a B2B ratings, and reviews company. But, as many as 25% of them don't tell their managers.

Even workers who don't currently participate in the gig economy say they want to: Nearly one in five (17%) are actively looking for a side job.

The new study suggests that as businesses adjust to the growing number of gig economy workers, they must evaluate their policies around employees having side jobs.

Without formal policies in the workplace, experts say employees have little or no legal requirement to disclose their work in the gig economy.

"[If] you don't expect the work to affect your primary job in any way, it's not unreasonable to simply proceed without disclosing it," said Alison Green, a management consultant who pens the Ask a Manager blog. "You're not obligated to disclose everything you do outside of work."

Respondents appear to agree because 25% of those with a side gig said they didn't tell their manager about it.

Green said that for most of them, that was probably not an issue: "If it's not a conflict of interest and it's not getting in the way of the person's work, the manager should stay out of it," she said.

Workers Use Side Gigs to Supplement Income

Most workers in the gig economy have the same primary goal: earn extra income outside of their day job.

Nearly 70% of gig workers identify income as the reason they work a side job. Gig workers often use that supplemental income to pay debts, increase savings, and spend on nonessentials such as travel.

The gig economy can also serve as a safeguard against unemployment, some workers say.

"[My side gig has] given me the freedom to know I can leave my job at any point," said Tim Stobierski, who works full-time and freelance writes. "It's given me peace of mind knowing that all of my income isn't tied to a single employer."

Companies Can Benefit From the Gig Economy

Although some employers might be wary of allowing their employees to take on additional jobs, many companies benefit from hiring gig workers.

Nearly 60% of companies hire gig workers. Companies can avoid the costs associated with recruitment and benefits by hiring freelance or contract workers for short-term projects or tasks that require specialized knowledge.

Companies are most likely to hire gig economy workers for assistance with technical tasks: Nearly one-third (28%) rely on gig economy workers for development, analytics, and IT services.

The study's findings strongly suggest that as the gig economy changes traditional norms surrounding work, companies must consider how the benefits and drawbacks impact their business.