In Ireland, a landlord generally cannot change the locks to exclude you from your home, even if there is a rent dispute or alleged arrears. Doing so may amount to an illegal eviction; a landlord must follow the proper notice and termination process rather than locking you out. Locks may sometimes be changed for security or repairs, but you should still be given continued access, such as a replacement key. If you are locked out, keep evidence, contact the RTB promptly, and consider speaking to a solicitor or the Gardaí if there is an immediate safety concern.