Grubb and Sons were a news agent in Stockbridge, England. They were the store at which Izzy Sinclair had standing orders for comic books, notably including Aggrotron. When given freedom of choice to go anywhere in the TARDIS, she urged the Eighth Doctor to take her to Grubb and Sons on 8 April 1988 so she could figure out why she was prevented from getting issue 56 of that comic as a child. (AUDIO: Izzy's Story)
Its exact relationship to Grubb General Store was not known.