What is the term used for an owner that is the same across multiple trademark files requiring updates?

The term that describes an owner who is the same across multiple trademark files requiring updates is "Common owner." This term is appropriate because it refers to a single entity that holds multiple trademarks and thus needs to keep track of any updates or changes across those registrations. Each trademark may pertain to different goods or services, but the ownership remains consistent, which is crucial for managing trademarks effectively.

The other terms, such as "Identical owner," may imply exclusivity or suggest that there could be variations in ownership, which is not accurate in the context of managing multiple registrations that share the same owner. "Multiple owners" clearly denotes more than one entity, which would not apply to this scenario. "Shared owner" could suggest a division of ownership, but the question specifies a single owner across the trademarks, making "Common owner" the correct and most precise term.