http://www.legislation.gov.uk/apni/1971/7/section/2Leasehold (Enlargement and Extension) Act (Northern Ireland) 1971An Act to enable lessees of certain premises held on long leases to purchase the fee simple interest in the land, to enable grantees of certain fee farm grants to redeem their fee farm rents, to enable such lessees to obtain an extension of their leases, and for matters connected with those matters.texttext/xmlenStatute Law Database2012-08-292009-10-01 2 1Where a person proposes to acquire the fee simple in the land or an extension of his leasehold estate in the land by virtue of this Act he shall serve a notice in the prescribed form upon each of the following persons who can be found and ascertained, that is to say,—athe person who is for the time being entitled to the next superior estate in the land; andbevery person (if there be any such person) who is, in relation to the land, a superior lessor of the person so proposing; andcevery mortgagee of the land (if there be any such person); anddevery owner of any other incumbrance affecting the land (if there be any such person).2It shall be a sufficient compliance with subsection (1)( a) if the notice is served on the person to whom the rent under the lease is paid.3Where for any reason whatsoever a notice served under subsection (1) is defective, the Lands Tribunal may allow the person who served the defective notice to serve an amended notice within such time and subject to such order as to costs as the Tribunal may determine.functions transf. 1982 NI 6