What is the determined % fee for my attorney to collect from the selling of my patent? What is his percentage in the selling (if has experience)? If doesn't have any but he success to sell it? If I got 4M, how much does he earn? The utility patent was already granted.
~ San Juan, CA
Congratulations on receiving your patent grant.
There is not a set percentage fee for an attorney to provide a service. Usually, attorney fees must be put in writing. With a percentage fee, or any type of contingent fee, the fee agreement also needs to be put in writing and signed by the client. Finally, all attorney fees must be reasonable, that is the amount of compensation has to be reasonable in light of the amount of work, experience of the attorney, amount of risk, and other factors.
It sounds like your attorney is already working for you. The easiest thing to do would be to ask your attorney to show you where his fees are defined in your agreement. If the sale of the patent occurs for a substantial amount, your attorney might be required to adjust the amount of the fee, if the fee is not reasonable.
For more information about attorney fees, you can read the American Bar Association's model Rule 1.5 for fees California, and all other states, usually adopt this rule or a similar rule. So, to know what rules apply to your situation, you will need to check your specific state's rules.
Good luck with the sale of your patent.