Whether you choose to work two full-time jobs out of necessity, or just because your career interests are diverse, consider the legal implications of potentially doubling your income before you commit to spending 16 hours working each day. Your current employment contract might restrict you from certain types of work, and you'll need to consider such factors as tax consequences, conflicts of interest and logistics in managing two careers.

Tip

It's not illegal to work two jobs, but it could violate your current employment contract and create a conflict of interest for your employer.

Tax Consequences

Earning a second income can certainly be appealing, especially if your current obligations total more than the income from your primary job covers. But if you are working as an employee versus an independent contractor, calculate your total income as you complete your W-4 for the second job. At a minimum, estimate your tax liability using the online IRS calculator, or consult an accountant or tax expert for advice on how many exemptions you should file and whether you should have additional monies withheld to cover the taxes due on your anticipated total income. Not paying taxes or accruing a tax liability that you cannot pay can cause serious legal issues with the IRS.

Conflict of Interest

If you signed an employment contract with your primary employer, taking on another part-time or full-time job may present a conflict of interest. For example, working a second job for a competitor is likely to be a conflict of interest because you have access to your primary employer's company records, practices and other insider information. Your primary employer wouldn't want to risk letting its proprietary information get in the hands of another company.

Also, the secondary employer shouldn't want to risk its reputation by the perception that it is privy to a competitor's information. For example, if you work for a recruiting firm that assists clients with resume preparation, your primary employer may not look favorably on you if your second job actually is your own resume-writing business. Even if your second job doesn't jeopardize your standing with your primary employer, maintain your integrity as a loyal employee and consider the optics of working a second job that leaves others to speculate whether you have compromised your ethics or principles. Some companies prohibit employees from engaging in moonlighting activities; check with your human resources officer to determine if you're even allowed to work another job.

Loyalty and Community of Interest

Some second jobs may call into question your loyalty or community of interest. Community of interest means are your values closely aligned with either job or is it difficult to justify why you're employed in two different types of jobs. For example, if you're a manager or supervisor on your primary job, yet your second job is in a union shop and you're required to join the union, working both jobs could be problematic. It's practically unheard of for a supervisor to also work a union job because this type of conflict raises questions about where you stand on the labor-management front. And if your co-workers find out your loyalties are divided in this way, it will be practically impossible to have collegiate working relationships on either job.

What About the Gig Economy?

Potential conflicts of interest may arise if you're considering working as an independent contractor as well. With the gig economy gaining popularity by the day, or by the service, working a second job doesn't mean you are working for another employer. Gigs or independent-contractor-type work for projects or on-demand services are essentially jobs that let you be your own boss, dictating when and where you want to work and how much you want to work. While gigs are famous for making work portable, if you have a steady primary job, the allure of gigs that permit you to work from anywhere may not be the appeal factor. But working on-demand jobs, such as driving for Uber, can present other challenges as a second job. For example, if your primary job requires you to be on-call, if you're driving an Uber passenger, it could be difficult to immediately report to your primary job.

Logistics Challenges

It might not be illegal to work two jobs, provided you have the time and can separate the two, but the ability to engage in moonlighting activities or gigging, or simply balancing the time necessary for two full-time jobs can present a challenge. To avoid potential conflicts of interest, time or logistics, manage your time wisely and be able to respond to questions about your level of attention to each job.