No, you can’t collect royalty on an expired patent

The owner of the patent has the right to stop anybody else from using the patented invention without permission (i.e., without a license from the owner), but only during the patent life term and not after the patent expires. Patent owners often agree to let others use the invention if the users pay “royalties” to the patent owner.  Sometimes, the user might even agree to pay royalties that continue even after the patent expires.   One example may be that the owner has many patents and the user wants to cover all of them with one contract. Another example may be that the arrangement might allow the user to make smaller payments in early years in return for larger payments in late years.   The Supreme Court held more than fifty years ago in its 1964 decision Brulotte v. Thys Co. that users cannot agree to pay royalties after the patent expires.   If they sign a contract to pay those royalties, the contract is invalid.   

This “no royalty beyond patent term” is reaffirmed by the Supreme Court in Kimble v. Marvel Enterprises, Inc. (March 31, 2015), in which the court hold that that a patent holder cannot charge royalties for the use of his invention after its patent term has expired.

So, no, you can’t charge a royalty after your patent expires.  Your patent license agreement needs to terminate when the last patent expires.

Thanks for reading.

cwan@patentonomy.com