Can Your Employer Legally Claim Code You Write at Home?
May 4, 2026 / 4 MIN READ / KlausClause TeamKlausClause Editorial Team
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Can Your Employer Legally Claim Code You Write at Home?
You're coding a mobile app on weekends, building something completely unrelated to your day job. Your employer finds out and claims they own it because you wrote it while employed. Can they actually do that?
The short answer: it depends on your employment contract, your state's laws, and how closely your side project relates to your employer's business. Many developers get blindsided by intellectual property clauses they signed without reading carefully.
The Work-for-Hire Doctrine Explained
Under federal copyright law, anything you create as an employee within the scope of your employment automatically belongs to your employer. This is called the "work-for-hire" doctrine.
But here's where it gets tricky: many employment contracts expand this concept far beyond what federal law requires. Your contract might include language like "all inventions, discoveries, and creative works made during employment" belong to the company. These clauses can potentially cover your weekend projects, even if you use your own computer and time.
The enforceability of these broad clauses varies significantly by state. Some states have pushed back against overreaching employer claims, while others give companies wide latitude to claim employee-created intellectual property.
State Laws That Protect Employee Side Projects
Five states have enacted specific protections for employee-created intellectual property: California, Delaware, Illinois, North Carolina, and Washington. These laws generally prevent employers from claiming ownership of inventions that:
- Were developed entirely on the employee's own time
- Were created without using company equipment, supplies, facilities, or trade secrets
- Don't relate to the company's business or anticipated research and development
California's law (Labor Code Section 2870) is the most employee-friendly. It explicitly states that employment agreements can't require employees to assign rights to inventions created on their own time without company resources, unless the invention relates to the employer's business.
If you live in one of these five states, you have stronger protection for your side projects. But even then, the "relates to company business" exception can still trip you up.
What "Related to Company Business" Actually Means
This phrase appears in most state protection laws and employment contracts, but its interpretation can be surprisingly broad. Courts don't just look at whether your side project competes directly with your employer.
Factors courts consider include:
- Whether your project uses similar technology or methods as your day job
- If it targets the same market or customer base
- Whether it could reasonably fall within your employer's current or planned business activities
- If you gained relevant knowledge or skills through your employment
A software engineer at a fintech company who builds a personal budgeting app might find their side project "relates to" their employer's business, even if the company doesn't offer consumer budgeting tools.
Safe vs. Risky Side Projects: Real Examples
Generally Safe Projects:
- A backend developer at a social media company creates a recipe blog with basic functionality
- A data scientist at a healthcare company builds a simple game app
- An e-commerce platform engineer develops a local community gardening website
- A cybersecurity professional creates educational content about cooking
Potentially Risky Projects:
- A machine learning engineer at Netflix builds a movie recommendation system
- A payments processor developer creates a cryptocurrency wallet
- A ride-sharing company engineer develops any transportation-related app
- A cloud infrastructure engineer builds developer tools for deployment automation
The riskier projects aren't automatically off-limits, but they're more likely to trigger employer interest and potential legal claims.
Practical Steps to Protect Your Side Projects
Review your employment contract carefully. Look for intellectual property assignment clauses, invention assignment agreements, and any language about work created during employment. Many developers sign these documents without reading them.
Document your project's independence. Keep records showing you developed your project on personal time, using your own equipment, without company resources or confidential information. This documentation becomes valuable if disputes arise.
Consider disclosure. Some employment contracts require you to disclose side projects to your employer. While this might feel risky, getting written confirmation that your project doesn't conflict with company interests can provide valuable protection.
Get legal review for valuable projects. If your side project has significant commercial potential, having an employment attorney review your contract and assess risks is worth the investment.
Use clean-room development practices. Avoid any temptation to reference company code, use proprietary algorithms, or leverage insider knowledge about market opportunities.
Be strategic about timing. Starting a side project before joining a company, or after leaving, eliminates many potential ownership disputes.
When Employers Actually Pursue Claims
Most employers don't actively monitor employee side projects. They typically only assert ownership claims when:
- The side project becomes commercially successful
- An employee leaves to pursue their project full-time
- The project directly competes with company products
- Someone reports the project internally
However, just because enforcement is rare doesn't mean the legal risk disappears. Employment contracts create enforceable obligations regardless of whether companies actively police them.
Understanding your rights and obligations upfront helps you make informed decisions about side projects. The goal isn't to avoid all creative work outside your job, but to understand the legal landscape so you can navigate it intelligently.
Have a contract to review? Try KlausClause.
This article is for informational purposes only and does not constitute legal advice.
Written with AI assistance, reviewed by the KlausClause Editorial Team. This is informational, not legal advice. For anything specific to your situation, talk to a licensed attorney.
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