If someone made a piece of software for another company but never gave away the intellectual property rights or signed anything, could they use that code in other similar software? Could they sell it?

Assume that they were not an employee of that company and that they never signed a contract of any sort with the company, but that they were paid.

  • 7
    Independent of the legal situation concerning this particular program: Unless you incorporated your company's or some 3rd party's IP in your software you can always recreate a similar software that does the same thing. Since you have done it once it may not be too difficult or time-consuming to re-write it with the knowledge that you now have (which is yours), without plagiarizing. It wouldn't be the first complete re-write in order to prevent copyright issues. Aug 17, 2020 at 10:18
  • 2
    @Peter-ReinstateMonica I've done this over and over with my set of support tools. In fact, while there's some wasted time for doing this again each time I get a new job, I also get plenty of better insight by the time the "rewrite" comes, and the tools really end up very different. And it's definitely much less of a walk through a legal minefield - if your software ever becomes successful, there's a good chance the company will at least try to get hold of your earnings, and even if you win, it can be a long run you're probably not ready for.
    – Luaan
    Aug 17, 2020 at 12:43
  • there was never a contract in the midle... That will not really help. With no existing contract, how can you prove that you are the sole author of the code? Even in a country where the author always keeps some rights on the produced thing, if there are many authors the copyright is shared, and all authors must agree for example to re-license a products - which is not so far of what you want to do: the original code was intended for one usage and you want to re-use it. Aug 17, 2020 at 14:15
  • @SergeBallesta Version control history may be sufficient to show authorship. Still being right doesn't mean cheap when it comes to legal action. Aug 19, 2020 at 1:36
  • Useful note is that if the company decides to sue you, it really doesn’t matter if you never signed anything. Court is a game of who can afford better lawyers, and who can afford to keep the battle going for longer. Lawyers are extremely expensive, and this situation is dancing along the edge of legality because in all likelihood a fair accusation could be made of “breach of oral contract,” “intellectual property theft” if you used any industry-specific knowledge from the company to make the first version, or if the company claims IP rights, and countless other crimes. Not a game worth playing Aug 28, 2020 at 3:21

5 Answers 5


For cases where this occurred within the United States, with works created on or after January 1, 1978: (the OP has since clarified that their scenario occurred elsewhere)

By default, the author (the actual creator) of a work is the owner of the copyright. However, this is not the case if the work is a "work made for hire" for an employer. In that case, the company is considered the author of the work, and owns the copyright. From US Copyright Office Circular 09:

If a work is made for hire, an employer is considered the author even if an employee actually created the work. The employer can be a firm, an organization, or an individual.

Works are considered to be made for hire in two situations, as described by that circular (emphasis added):

a) a work prepared by an employee within the scope of his or her employment


b) a work specially ordered or commissioned...if the parties expressly agree in a written instrument signed by them that the work shall be considered a work made for hire.

If no written agreement was signed and no employment relationship existed, then ownership of the copyright to the software would go to the person who wrote it, and they would be able to do anything that a copyright holder could do with a work, including using it however they want or selling it.

Do note that this would only apply to software or changes made by the person in this situation. They could not, for example, sell or distribute any other piece of the software written by other people without the copyright holder's permission, even if these pieces are necessary to use the software that this person created.

  • So i can do whatever with the code or software? Becouse there was no contract or anything that says that I give the permition so im the autor and IPR belongs to me.
    – Illud
    Aug 17, 2020 at 5:03
  • 7
    @Illud I cannot interpret how the law applies to you specifically, as that would be legal advice, and I am not your lawyer. A person in the situation I described in my answer could do whatever they wanted with the software (other than, obviously, using it to commit other crimes), subject to the constraints I described in my answer. You may infer for yourself how that applies to you.
    – Ryan M
    Aug 17, 2020 at 5:06
  • 4
    @Illud this is a question for your lawyer, taking into account your specific situation and any agreements / contracts you had. We can’t help. I’ll also note that it’s very difficult to read your comment with the number of typos. Please be careful when writing to help make sure everyone can understand.
    – Tim
    Aug 17, 2020 at 16:56
  • 4
    @Illud Getting paid for your work but without a written contract stipulating what exactly is being paid for greatly complicates things to the point that I doubt anyone who isn't a copyright lawyer in your jurisdiction would be able to help. You would be wise to assume that you don't own the intellectual property until your lawyer tells you otherwise.
    – aleppke
    Aug 17, 2020 at 17:42
  • 1
    I came across while looking for the this answer. Excellent :)
    – Vega
    Aug 24, 2020 at 7:56

This varies with jurisdiction.

(Since OP appears not to be in the US this is important)

In the US the company would retain copyright IF you were an employee or if there was a written agreement stating they own the copyright.

However in NZ if a company paid you for the work then they own the copyright.

In AU, who retains copyright depends on the medium (i.e., journalism is treated differently than software)

When the company is in one country and the author in another, it gets... complicated.

There has been some US case law, where the copyright law of the authors country takes precedence. But in that case that was a win for the US company. Don't count on that if it meant a US company loses next time. [End cynicism]

Please consider also the cost (money and time) if they sue. Even if you win it is going to be a PITA.

Also the next company you do work for is not going to be happy if they get sued (even if they win).

This could have long term damage to your reputation and perceived reliability.


There was a contract between you and the company, it just wasn’t written down. If the company sued you for copyright infringement - which the can do whether they own the copyright or not - the judge would decide based on the actual facts what kind of contract there actually was. And that would decide who is the copyright owner and what rights you and the company have.

  • 1
    I don't believe this is correct. Only a written contract can specify authorship for copyright purposes in the US. If there is no written contract, then the statutory rules apply. That means the individual creator(s) is/are the author(s) unless they were employees acting within the scope of their employment (or in a few other special cases specified by law not relevant here). Aug 17, 2020 at 9:20
  • Well, that’s the question then. If there was a contract saying that I either work as an employee, or as a contractor, without mentioning copyright, then the outcome would be clear, as you say. Without a contract, the judge would have to make the difficult decision whether I was an employee or a contractor. That’s the hard part. Once that difficult decision is made, it’s easy to decide who owns the copyright.
    – gnasher729
    Aug 17, 2020 at 12:30
  • @gnasher729 Isn't that easy to decide based on which tax form was filled out? (In the US) Aug 17, 2020 at 19:39
  • What if it was cash in hand? Ok, that’s probably some kind of offence, but makes it harder to decide.
    – gnasher729
    Aug 19, 2020 at 15:50

I am inferring your level of legal experience from the way you wrote this. (which is to say, quite little). And as you say in comments, you are in Colombia.

Nope, cannot do it.

It is a complete lose to even try, because of the hoops and hurdles in your way, many of which are dead-ends.

When an employee creates "work product" as part of their employ, that is property of the company and intellectual property rights go to the company.

You can claim that property right only if you can claim that you were not an employee at all, but some sort of creative contractor (where's your contract, contractor?), and further, that the nonexistent "contract" conferred the IP rights of your paid work to yourself and not the payer. See where that's a bit of an uphill proof?

This will play out in court, one of two ways: #1. You go to court and ask the court to rule that the intellectual property belongs to you, in advance, before you start using the IP with other companies. Or, #2, you just go ahead and use it anyway, AND the first company gets wind of this, AND the first company decides they want to sue.

In the first case, you are choosing the fight in a low-impact, low-risk way: worst case the judge says "no" and you pay the old company to license the material, or walk away and create new material.

In the second case, it's less likely to happen, but if it does happen, it is devastating. You could find yourself being attacked from both sides (because company 2 would feel this is NOT their fault and you misled them). Company 1 would sue for all company 2's profits, and both companies would agree you should pay it.

Is it better to fight, or rewrite?

And here's how I definitively get to a "nope".

I don't know how expensive litigation is in Colombia. But I can tell you, it's a gigantic emotional energy sink also. It devastates your productivity as a creator. One person wrote amazing tech manuals (site gone), until this happened and the creative spigot just stopped. See what I mean about "distraction"?

The employer owns your work product; they do not own your mind. You can re-create the work from scratch. Turn heel and walk away from the original work and make a new and better one.

And this time, get it in writing lol....

  • I never sign a contract or give the IPR, actually the new software have nothing to do with what it was is a totally a diferent thing. i also have a document that says that the say that i can do what i want with the new software and is sign by my ex boss.
    – Illud
    Aug 17, 2020 at 23:47
  • @Illud End of the day, it's between you and your lawyer, and your confidence level at walking into the court with the papers you do have. Aug 18, 2020 at 19:25

I am probably the least knowledgeable person in this site when it comes to law, but I do write software for a living.

I believe IP laws and jurisprudence might see code in a way that is similar to other forms of IP. So I will use an example from music.

Last year a federal judge in the US ruled that Katy Perry's song Dark Horse infringed on the copyrights of rapper Flame's song Joyful noise. The songs have nearly nothing in common - the infringement was due to an eight note ostinato that wasn't even the same among the songs.

Music specialists pointed out that a myriad of other songs have the same kind of ostinato, being as similar to Joyful Nise as Dark Horse is. Most examples I could find online are in the public domain because their authors have been dead for a few centuries. A similar lawsuit made against Led Zeppelin had a more sensible outcome, which helped overturn the results of Flame vs. Perry (saving the latter some 2.8 million USD).

I found a couple videos that elaborate on this:

The bottom line is that as with all intellectual property, some parts of a work are protected, some other parts are not1. Consider that when thinking about using code that you wrote for another company. Small functions and variable declarations in code are like sequences of musical notes. What is the threshold that makes one song different from another?

Are you reusing a library that you wrote in your last job, with references to the company by name and everything? Probably a no-no.

Are you using the same algorithms and logic, wrote in a different way, decoupled from the previous company's business? Possibly in a different language, and covering more use cases? Might be worthy talking to a lawyer in person for legal advice, as this has the potential to become a new product, but might still be infringement. You might like to read about Google vs. Oracle America (I read that Google's lawyers were using the same philosophy as I'm using here, but using Harry Potter instead of Katy Perry as an example).

Are you able to solve the same problem with different algorithms? You may be a better coder now than you were before. You can probably outdo your former self and do something that is new and unique enough that you can be more at ease when it comes to copyright. Be mindful about non-competition clauses your old contract might have, though. And again, seeing a lawyer personally will save you a lot of trouble.

1 Were it not so I would be a trillionaire. I wrote int i = 0 in 1993 and now every single programmer in the world that did the same after I did would own me 25 cents for every day in their lives they have written code :D I might have to pay larger sums to the original C++ authors from the 70's though.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .