The question was asked on the Kitmeout forum: what’s the difference between TJ Maxx & TK Maxx? And what does TJ and TK stand for? The answer was deflating:
Thank you for contacting T.J. Maxx Customer Service.
While we would like to provide you with some kind of story or anecdote regarding the names, we can not. Thanks to a great Marketing team who liked the way T.J.Maxx sounded, the name stuck. As far as T.K. Maxx goes, they wanted a name that was similar to T.J. Maxx that people could identify with. However, because they are two separate chains, the names had to be slightly different.