If you've used all five choices and are not holding any offers, you may be able to use Extra to add another choice.
This allows you to add a new choice to your UCAS- for more information visit
Extra is normally open between:
February-June.
For more information:
https://www.ucas.com/ucas/undergraduate/apply-and-track/track-your-application/extra-choices
https://www.ucas.com/undergraduate/after-you-apply/types-offer/extra-choices