Board Thread:The Reference Desk/@comment-7657843-20161112133450/@comment-5918438-20161112214726

There is no official list or definition of a Doctor Who spin-off.

According to some interpretations, Doctor Who Extra and Doctor Who Confidential might count as a spin-off. K9 might not even count, according to some definitions, as it's not BBC-licensed and merely features a major character from the Doctor Who universe.

See our page Doctor Who spin-offs for our list of spin-offs.