What is a key requirement when submitting updates for a trademark registered under multiple owners?

When trademark updates are required for a trademark registered under multiple owners, the key requirement is to submit separate updates for each owner. This necessity arises because each co-owner holds an independent interest and rights in the trademark, which means that updates such as assignment of rights, changes in address, or other modifications must be clearly communicated to the USPTO for each owner involved.

By submitting separate updates, each owner's information is correctly represented in the USPTO's records, ensuring that all legal rights and obligations associated with the trademark are properly documented. This process helps in maintaining clear ownership and accountability among the co-owners of the trademark.

The other options do not adequately address the required procedures: validation from the USPTO is not a direct requirement when updating ownership details, an increase in fees might occur depending on the updates made but is not a core requirement, and only updating the primary owner is insufficient because it neglects the rights and responsibilities of all co-owners. Thus, ensuring that each owner is separately updated aligns with the principle of protecting all parties’ trademark rights.