It sucks, but if you wrote it for hire and didn't specifically license it to them, they own it and they can do whatever they want with it. If you want to avoid

It sucks, but if you wrote it for hire and didn't specifically license it to them, they own it and they can do whatever they want with it. If you want to avoid this in the future, write up a license agreement with your lawyer (1) that spells out that the client is licensed to use it but not resell it, etc. You create the software on your own time and then license it to them. On top of that, you can charge a normal contractor rate to integrate it into their systems (if they want you to). Here is the relevant part from a license for a library I made: "Licensor hereby grants to Licensee, for the term of this Agreement, a nonexclusive, nonassignable, right and license to use the Software on the machines it sells for the purpose of, but not limited to, implementing a _______. Licensee may use the Software in executable format for its own use, and may translate or modify the licensed programs or incorporate them into other software. Licensee may not, however, transfer or sublicense the Software to any third party, in whole or in part, in any form, whether modified or unmodified." On the subject of contracts. You should should be making these (with a lawyer). Otherwise, you are a the mercy of the clients contract. When you write the contract, you get to set the terms. (1) Yes, a real lawyer. You should also draw up a services contract for your normal consulting. It will save you money in the long run.