Freelance client work while employed: check before you start

This guide is general information, not legal advice. Employment law differs by country and, in the US, by state. If real money or a real risk is involved, a short consultation with an employment lawyer costs less than a dispute.

Start with what you signed

Pull out your offer letter, employment agreement and any policy documents you accepted. Read for five things.

1. Outside work or moonlighting clauses. Some contracts ban outside work entirely. Some require permission. Some only ban work for competitors.
2. Conflict of interest language. Often a separate policy. It may cover clients, suppliers, or anyone doing business with your employer.
3. Invention or IP assignment. Some employment agreements say that work you create belongs to the employer, and the wording can reach beyond work done on company time.
4. Confidentiality. What counts as confidential, and whether it covers ideas, customer lists or code you saw at work.
5. Non-compete and non-solicit. These can limit who you can work for after, and sometimes during, employment. Whether they can be enforced varies a lot by country and, in the US, by state.

Employer-side guidance shows what these clauses usually look like. A Wolters Kluwer article for employers says basic moonlighting policies generally cover interference with the primary job, conflicts of interest, and the employer's approval of additional employment. Its sample wording includes a clause asking staff to discuss outside work with a supervisor before accepting it, and another requiring written permission for outside work with anyone doing business with the employer. A Lexology article on Canada says employers who worry about moonlighting are advised to put a conflict-of-interest or exclusivity clause in the contract, which works alongside unwritten common law protections such as an employee's duty of loyalty. The first is written for US employers and the second for Canadian ones, so use them as a checklist of what to look for, not as a statement of your rights.

The IP question is the one to understand

The practical fear is simple: you build something for a client or a side project, and your employer claims it. Whether they can depends on the contract and the law where you live.

California has a statute that shows the shape of the issue. Labor Code section 2870 says a provision in an employment agreement that makes you assign an invention to your employer does not apply to an invention you developed entirely on your own time, without the employer's equipment, supplies, facilities or trade secret information. There are two exceptions: inventions that relate to the employer's business or its actual or demonstrably anticipated research and development, and inventions that result from work you did for the employer. The statute also says that to the extent a contract tries to require more than that, the provision is unenforceable as against California public policy.

We opened that text on 2026-10-09. We did not research other states or countries, though some have comparable laws. Do not assume the same protection applies where you are.

What it teaches, wherever you live:

• Doing the work on your own time with your own equipment and accounts is the baseline.
• "Related to the employer's business" is where disputes start. If your day job is e-commerce software and your side client wants an e-commerce plugin, you are close to that line.
• The words in your agreement matter more than a general idea of what is fair.

Conflicts and competitors

The Lexology piece makes the same point from the employer's side: a ban on working for a competing business is often enough for them, while a part-time job in an unrelated field is less likely to hurt the employer if you give your full attention at work. Employers care most about competition and distraction, so avoid:

• Clients who compete with your employer.
• Clients your employer works with, unless you have permission.
• Any use of employer knowledge, contacts or code.

If you freelance in the same niche as your job, ask permission. The answer might be yes, and you will have it recorded.

How to ask permission

Short email to your manager or HR, and keep a copy. For example:

"I'm planning to take a small amount of freelance web development work outside work hours, using my own equipment. It won't involve [company's product area] or any of our clients. Is that okay under my agreement, and is there anything you'd like me to avoid?"

Possible answers: yes, no, or send us the details. Each is useful. A vague verbal "should be fine" is not.

Keep the two lives apart

• Use your own laptop, email address, repository accounts and cloud accounts for client work.
• Do side work outside working hours. Do not take client calls on your employer's time or in their office.
• Never copy employer code, templates or documentation, even "just a pattern".
• Keep your own clients' data off employer systems.
• Do not use your employer's name in your portfolio or pitch without permission.

Protect the side clients too

Your client agreement should say who owns what and when. A common structure is that ownership of the deliverable transfers to the client once they have paid in full, while you keep your own tools and general know-how. State that you are an independent contractor and that you have the right to provide the service, which you will if you did the checks above.

If you have an existing side project, check whether your agreement has a place to list prior inventions or projects, and keep dated proof of what you built before you joined.

Money, tax and status

Freelance income is generally taxable income wherever you live, usually on top of your salary. Rules for registering, invoicing and paying tax differ widely, so check your country's requirements before your first invoice. If you work on an employment-based visa, check whether outside work is allowed at all.

Finding the first client while you have a job

You have less time, so spend it well. Pick one kind of work. Small, well-defined jobs fit around a full-time role better than open-ended builds. Agencies can suit this stage, since they hand you scoped tasks; see subcontracting for agencies as a freelance developer. If you build automations, get your first automation clients without Upwork covers routes that fit evenings. Be honest about your availability with every client, and do not promise same-day replies you cannot give.

Where Thomas Partners fits

Thomas Partners finds client work for freelancers and runs the outreach; you keep most of the profit.

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