ACT writing portion

I have taken the SAT w/ essay, as well as the ACT with essay. I am taking the ACT again on saturday, hoping to get a better score. For colleges who require the essay, if I send my old score with essay, and my new one (and probably the higher score), will they not accept the new one since I didnt take the essay with it? Or will they accept it as long as I send my test with the essay? Thanks!