There is an answer but it betters 9.
Desmond Lewellyn !
He has been in 17 of the 20 Bond films already made and died just before the 20th was made. The record was almost there in Diamonds are forever having been in 6 - all but Dr No of the series and then after Diamonds are forever, they made Live And Let Die and he was not in that one. Then astonishingly the record is started with The Man with the Golden Gun and he was in every official MGM Bond film through to and including - The World Is not enough
Making the record with Desmond Llewellyn having been in 10 consecutive Bond films.
They are all consecutive and part of a series and after most of the films they announce another - so I think they can be classed as sequels - there are ongoing characters, threads and the films have a formula - so I am positive they are sequels.
After all James Bond Will return in ............................
Oh yes and Judi Dench has not been in 9 Bond films !
Goldeneye, Tomorrow Never Dies, The World is not enough & Die Another Day she's 5 short !!