I have filled that standard form where you list your previous inventions before starting your new job so the employer is legally aware you have the copyright over them. But if I want to use this invention (software code / framework) in my new job, would they have any copyright claims on it if for example I change / improve something on my code while working for them?

I have heard something like a shared ownership. Something like: you would own what was done before and employer would own any improvements you did on it while employed. That kind of sucks and take away any incentive you would have to do improvements on your product since once improved, the improvement is gone. :(

Has anyone gone through this situation before and could share some ideas so I can protect my code?

  • Have you considered open-sourcing your previous invention? How about selling it to your new company on an as-is basis for a nominal fee? Then you could just re-sell it to them any time you make improvements. Feb 7, 2013 at 14:29
  • @Baqueta I have other things that I open source, but this particular project is not in my best interest to open source it. I plan to sell it later to other companies and/or use it again in other assignments I may have and/or other jobs. Feb 7, 2013 at 15:09
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    @Baqueta - Making the project open source does nothing about future work being controlled by a restrictive IP agreement. The company must release any claim to John's work in order for him to continue working on it.
    – user53019
    Feb 7, 2013 at 15:15
  • Have you considered selling them the current version of the whole thing and transfer ownership to them for an adequate price? If you insist to keep ownership, your new employer could insist that you are completely responsible for the maintenance that software, 365 x 24h per year.
    – Doc Brown
    Feb 7, 2013 at 15:21
  • @GlenH7: Wouldn't one of the copyleft licenses force the work to remain in the public domain? JohnPristine: Fair enough! Feb 7, 2013 at 15:25

4 Answers 4


Apparently, you want to retain ownership of that software.

If this is so, simply do not sign a contract that takes it away from you.

The normal case, however, is, that what you produce during your working hours is owned by your employer. Your renumeration should be compensation for that.

Maybe you can reach an agreement, where the hours you work on imporvement of that invention are not counted (and paid) as working hours. Instead, your employer agrees to buy (a license for) the improved version for approximately the same amount as you woulod make in those hours.

  • One solution may be that I will ONLY make improvements during my off-ours. But the company would probably not agree to have something dependent on a close-sourced product/framework. I don't mind showing them the code and they can do modifications if they want/need in the future. But I would like to keep ownership in the product and in the code like you said. Feb 7, 2013 at 15:11
  • @JohnPristine it really depends on how badly they need it. Look, they probably depend on close-sourced Windows. OTOH, if you give them a source code license, it is not closed source anymore.
    – Ingo
    Feb 7, 2013 at 15:14
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    "They can do modifications if they want/need" = you doing the modifications for them. and if they make modifications they own those modifications unless you can convince them to officially push them "upstream" Feb 7, 2013 at 15:28
  • Additionally, if you make updates/improvements in your work version of the application, then try to add those same updates to your personal version, it leads to them potentially being able to bring legal action against you for infringing on "their property".
    – BBlake
    Feb 7, 2013 at 18:03
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    Alternatively, why don't you grant them a license to use the software in exchange for the right to keep copyright over your own changes? They get the software, and you still own the updates. It should be win-win. Unless they want to sell your software to other people, in which case, I'd sell a license for them to do that, and negotiate for a cut of the profit. Feb 8, 2013 at 6:55

It really depends on what is in your employment contract.

I had to ask to have a specific clause added to my contract that allows me to work on open-source projects in my spare time. The original contract claimed all copyrighted material that I produced during the period of my employment, whether I was at work or not.

If it is not explicitly stated in your contract, local labour laws would likely apply, and you'd need to consult a lawyer. You might need to anyway - there are certain rights that you simply can't sign away, no matter what a contract says.


This is a simple problem. You need to make sure there is an intersection between your interests and your employer's interests in this matter.

Does your new employer even care about using your code? Do they want it? If so, then add it to your agreement that any modifications to that code:

  1. you retain copyright to
  2. they retain full, unlimited, permanent, transferable, sublicensable, etc... licence to use, reuse, etc...

If they are too big to do that, then simply don't take your software there.


Maybe the best thing to do is to open source it first, with maybe an MIT license. Then, use it at your new job. The new employer wouldn't be able to claim ownership of an open source project that was created\released before your employment began.

Shared ownership sounds messy. I can't imagine that scenario being best for you, but I can see the company getting the better end of that arrangement.

  • Open source for this particular project is not on my best interest. I have other things open source it. Feb 7, 2013 at 15:09
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    This is a bad, if not terrible, suggestion. Placing the project under an MIT license will protect the existing code, but does nothing for future development. Under a very restrictive IP agreement, all copyright for future work belongs to the employer. Your suggestion puts the asker in conflict with his work agreement if he makes new contributions to the project. He cannot legally contribute something he does not own.
    – user53019
    Feb 7, 2013 at 15:13
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    OP is not interested in taking ownership over what his company does to modify the project. He's interested in keeping control over what he's already built. Edit: Read some of OP's other responses; I'd just declare the work as pre-existing and not use it with your new employer. Feb 7, 2013 at 20:14
  • @KamauMalone - Not using it is the best suggestion I have seen. Why complicate matters...the author wants to sell his product he should keep his personal business seperate from his work with this company. He should not even work on ANYTHING connected to his product to be honest.
    – Ramhound
    Feb 8, 2013 at 12:05
  • It is just infrastructure code that I want to use in other places. Feb 8, 2013 at 12:54

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