http://www.legislation.gov.uk/apni/1964/36/section/40Business Tenancies Act (Northern Ireland) 1964An Act to provide security of tenure for certain tenants occupying premises for business, professional or certain other purposes by enabling them to obtain new tenancies in certain cases or in certain circumstances to obtain compensation; to make provision for the payment of compensation in respect of certain improvements to such premises; and for purposes connected therewith.texttext/xmlenStatute Law Database2013-02-182009-10-01 PART II401Where—aa tenant has duly served a notice of improvement and neither a notice of undertaking nor a notice of objection is duly served in respect of that notice and the tenant executes and completes in accordance with that notice the improvement mentioned therein; orba tenant duly executes an improvement in accordance with an improvement order; orca tenant duly executes an improvement in pursuance of a statutory obligation;the landlord of that tenant shall, on the application of the tenant, give to the tenant a certificate (in this section referred to as an “improvement certificate” ) that the said improvement has been duly executed, and if the landlord refuses or fails within one month after the service of the application to do so, the tenant may apply to the Lands Tribunal who, if satisfied that the said improvement has been duly executed, shall give a certificate to that effect.2Where a landlord gives his tenant an improvement certificate under this section, the tenant shall be liable to pay any reasonable expenses incurred for the purpose by that landlord, and if any question arises as to the reasonableness of such expenses it shall be referred to and determined by the Lands Tribunal.