Intellectual Property (IP) Law protects and covers creative property which are intangible assets and “creations of the mind,” such as artistic work, music, designs, symbols, and inventions. It is important to know that unless you give them away, you are the sole owner of the creations of your own mind.
This is also true even if a client pays you for your work, the exchange of money and services is not the same as Intellectual Property Rights changing hands, especially if you have never had a contract with a client stating that they own the IP, the IP rights remain yours.
As a freelancer your Intellectual Property is your livelihood, your created products are your own. When you are working for a client you must know that your client is paying your for the rights to use your intellectual property not to own it. As a freelancer it is very important to ensure you are vigilant with the ownership rights to your intellectual property.
As a freelancer you should always want to keep the rights to your intellectual property or grant only the minimum rights possible.
Here is a scenario for you: Say you are a blog writer, ideally you would want to grant your client the use of your intellectual property for a limited time, after this time they would no longer have rights to your work and you would still have ownership throughout. You also want to ensure a clear schedule is outlined. You still own the work however you give the hosting blog the right to post your content or remove it when requested at any time. This will also mean that your name is attached to your work so you get the credit, this is also good for your career, organic referrals and analytics as readers may google your name. Also, if you want to use your intellectual property for further profit, you have the right to as you own it.
Another option could be that you grant the client ownership rights to your IP for a limited time for an extra cost additional to what is outlined in the contract.
It is also wise to state in any contracts, drafts of work that the right to use your work is granted upon full payment, this can help avoid clients who are late on payments.
Ensure if you have granted rights for a limited time that you stipulate in the contract when the rights revert back to you.
If your IP is stolen or your client never pays you it is important to reach out to the client directly to come t a resolution. If there is no resolution, contact an attorney. You can also reference this document Reporting Intellectual Property Crime