I built something cool at home…but my company says it’s theirs.. Now What?

You finally did it. After work, on weekends, and in those “just one more hour” late nights, you built something genuinely cool at home, a new product design, an app, a device, a process, a logo/brand concept, maybe even a whole side business. Now you hear yourself saying, “I built something cool at home…but my company says it’s theirs.”

That moment is a gut punch. It feels personal. And it can get messy fast—because in many cases, the answer isn’t as simple as “I made it at home, so it’s mine.”

Let’s talk about how these disputes really work, what matters, and what you should do next if your company is claiming ownership over your side project.

Why your company might claim your side project:

Most people assume ownership is obvious: you built it on your couch, on your own laptop, on your own time. But employers often rely on paperwork you signed—sometimes years ago, during onboarding, saying that inventions or creative work related to the company’s business belong to the company.

These are commonly called:

invention assignment agreements
IP assignment clauses
proprietary rights agreements
confidentiality agreements with “inventions” language

And here’s the key: many of them are written broadly on purpose. Some basically try to scoop up anything you create while employed, whether you built it at home or not.

Think of it like a fishing net. Some employers use a reasonable net size for “work-related inventions.” Others toss a net so wide it drags half the ocean.

The “big factors” that decide who owns what

Every case is fact-specific, but these are the issues that usually matter most:

1) What did you sign?
This is ground zero. The contract language controls a lot. Some agreements claim:

anything related to the company’s business
anything created using company resources
anything created during your employment
anything that “results from” your work at the company

Even if a clause seems unfair, it can still cause major problems if you ignore it.

2) Did you use company time or resources?
This includes obvious things like:

building it on your work laptop
using company software licenses
emailing yourself materials from work
using company tools, lab space, or testing equipment

However, it can also encompass less obvious aspects, such as developing it during work hours, on breaks, or while traveling for work. Even small facts can get spun into “company resources were used.”

3) Is your invention related to what your company does?
If your employer sells medical devices and your side project is a new medical device concept, expect a fight.

If your employer is in logistics and you built a scheduling platform, same.

The closer your side project is to the company’s industry, customers, or product roadmap, the more leverage your company may have (or try to claim).

4) Did it grow out of your job duties or confidential knowledge?
Even if you built it at home, your company may argue:

You only knew the problem because of your job
you used inside information, data, or methods
You developed it because it was part of what they hired you to do

That doesn’t automatically mean they win, but it’s often the argument.

5) Did you disclose it—or were you required to?
Some policies require employees to disclose outside inventions or side businesses. If you didn’t, the company may use that to pressure you, even if the underlying ownership issue is debatable.

Common misconceptions that get people in trouble

“I did it on my own time, so it’s mine.”
Sometimes true, sometimes not. The contract and the relationship to the employer’s business can change the answer.

“I never told anyone at work.”
Keeping it quiet may help, but it doesn’t erase a signed assignment agreement.

“It’s just an idea.”
Ideas alone are usually not protected the same way a developed invention or tangible work is—but once you’ve built something, documented it, filed for protection, or launched it, the stakes climb quickly.

“I used my own laptop.”
Good. But if you used company software, data, prototypes, customer info, or work time, the company may still claim involvement.

What you should do if your company claims it:

1) Don’t panic-text your boss or “explain it all” in an email
In these disputes, one emotional email can become Exhibit A later. Keep communications calm and minimal.

2) Gather your evidence while it’s fresh
Start pulling together:

timeline of when you started and key milestones
proof you worked on it off-hours
hardware/software used (personal vs. company)
drafts, commits, sketches, notes, prototypes
any onboarding documents and policies you signed

The goal is to create a clean, credible story supported by documents.

3) Stop using anything that could be seen as company resources
If there’s any overlap, cut it off now. Don’t access work files “just to check something.” Don’t forward documents. Don’t use work email.

4) Get legal advice before you negotiate
A lot of these cases resolve through negotiation, sometimes quietly, sometimes with an agreement that sets boundaries, licenses rights, or confirms ownership.

But negotiating without counsel is like walking into a high-stakes card game while the other side gets to see your hand.

How a lawyer helps in a side-project vs. a company dispute:

These situations often look simple on the surface and complicated underneath. A lawyer can help by:

reviewing the exact language you signed (and spotting overreach)
analyzing how your state’s law treats invention assignments and employment IP
structuring your evidence so it supports your ownership story
communicating with the employer in a way that protects you and de-escalates
negotiating a clean resolution (confirmation of ownership, carve-out, license, or settlement)
helping you avoid the “unforced errors” that turn a manageable dispute into a lawsuit

Most importantly, we can help you protect the value of what you built, because once a company starts claiming ownership, the goal often becomes control. Control over the IP, the product, the launch, and sometimes your ability to keep working on it at all.

If you built something at home and your company says it’s theirs, don’t assume you’re stuck, and don’t assume you’re automatically safe either. The outcome usually depends on a few big things: what you signed, how closely the project connects to the company’s business, and whether any company resources or confidential information were involved.

If you’re dealing with this right now (or you’re about to launch something and you want to avoid a fight before it starts), it’s worth getting legal guidance early. The right strategy can prevent a blow-up, protect your side project, and help you move forward without stepping on a legal landmine.

If you want to talk through your situation, call Tucker Law at 1-800-TUCKERWINS.