What makes an assignment effective
U.S. patent law requires assignments to be in writing. An assignment transfers ownership of the patent or application, unlike a license, which grants permission while the owner keeps title, and courts look at substance, so an exclusive license that transfers all substantial rights may be treated as an assignment. Wording matters in employee and consultant agreements too. Language that presently assigns future inventions generally works differently from a promise to assign later, and courts have treated that difference as decisive in ownership disputes. Each patent and application should be identified clearly, including related applications and foreign counterparts if they are meant to be included.
Recording with the USPTO
Assignments can be recorded through the USPTO's assignment recordation system. Recording is not what makes the transfer valid between the parties, but it protects the new owner against a later buyer who pays without notice of the earlier transfer, and that protection depends on recording promptly. Gaps in the recorded chain, such as an unrecorded merger, an entity name change, or an inventor assignment that was never filed, tend to surface during diligence or litigation, when they cost more to fix.
Co-ownership and diligence
When a patent has more than one owner, U.S. law generally allows each co-owner to use and license it without the others' consent and without sharing the proceeds, unless they agree otherwise, which surprises many people. Co-owners also usually need to join together to sue for infringement. Before an assignment is signed, we review the recorded chain of title, existing licenses and security interests, and any government or university rights attached to the patent. Bring the patent numbers, the agreements under which the inventions were made, and any earlier transfer documents.
