I've written an open source library for iOS, and I've received an email from an overseas developer who wants to pay me for my work so that he doesn't have to attribute in his app.

The code is released under the MIT license, which allows for reuse so long as the license is distributed along with the code. I told him that he can just use it without attribution, but he insists on sending me something.

What's the practice in the open source community, bearing in mind that several others have contributed to my library? Is there a standard or convention in the OSS community for this sort of thing?

  • 6
    This question appears to be off-topic because it is about legal advice. You should consult a competent legal professional, not a bunch of people on the internet.
    – Ampt
    Nov 28, 2014 at 5:29
  • Your modification of the MIT license means it's not the MIT license anymore. You can license your software under multiple licenses, some of which may only be available for charge. Is your question about dual-licensing software, or concerns about taxation and other economy funstuff that may arise due to dealing across nation borders? Nov 28, 2014 at 5:39
  • @Ampt, edited - not just legal.
    – Moshe
    Nov 28, 2014 at 5:41
  • 1
    @Moshe It still appears that the main part of this question is "Can I legally do this" which is a question that can only truly be answered by a legal professional. You'll feel awfully silly if we tell you the wrong thing and you get yourself in legal trouble.
    – Ampt
    Nov 28, 2014 at 5:44
  • 2
    If you do accept money for it (and I fail to see any reason not to), just make sure its via paypal or something similar. I would not recommend accepting paper checks, or handing out your bank acct info. Nov 28, 2014 at 5:45

2 Answers 2


In principle, there is nothing wrong with accepting payment for software you provide, not even if that software is freely available through other channels.

Some gotchas to look out for are:

  • Bank account details are loved by criminals. If possible, prefer to use services like PayPal.
  • Be careful with what you promise and what contracts you sign.
    • What level and duration of (free) support are you are entering into
    • If the contract states the software is written for/on behalf of someone, you may be signing over your copyrights. Be sure to review it with a lawyer before signing.
  • If you get paid regularly or large sums, you may have to pay (income) tax over it.

If the buyer wants to do something that isn't possible under the current license, you can give them a version under a different license, provided that either you are the sole copyright holder, or all copyright holders agree, or the license explicitly gives you the right to sub-license the work.
But in no case should you allow the buyer to remove the copyright statements from the source code, as that probably indicates they want to claim the work as their own.

  • 1
    +1. Also in the contracts make sure you are not providing any warranty that the code actually works. (To avoid potentially being sued later.)
    – MarkJ
    Nov 28, 2014 at 13:30

Your biggest problem is the other contributors. Unless you have a written agreement with them, they own the copyright to the bits they contributed. This means you need to get all of them to agree to release the software under a different license.

Established projects require all contributors to sign a contributor's license agreement. If you have done this, whether you can accept payment for a dual license depends on the wording of the agreement.

Not the answer you're looking for? Browse other questions tagged or ask your own question.