Residential Tenancies Act 1986

Where a tenant remains in occupation of the premises after the tenancy has terminated or has been terminated, all the obligations of the tenant shall continue in force as if the tenancy were still subsisting until such time as the tenant ceases to occupy the premises.

If the landlord permits the tenant to remain in the premises for more than 90 days after the tenancy has terminated or has been terminated, without obtaining a possession order, or for more than 90 days after obtaining a possession order, the landlord shall be deemed to have granted, and the tenant shall be deemed to have accepted, as from the date on which that period of 90 days expired, a periodic tenancy of the premises on the same terms and conditions as pertained to the original tenancy immediately before its termination.

The landlord shall not be taken to have permitted the tenant to remain in possession, or to have given up the right to proceed under this Act in respect of any breach of the tenant’s obligations, merely because the landlord accepts payment of rent in respect of any period after the tenancy has been terminated.