Overreaching Interest is a term in English land law.
Overreaching can only exist where a trust is in existence and a property is sold. The occupiers of a property in such a situation cannot then claim that their occupation of the property is an overriding interest, as the joint trustees have brought that occupation to a close through the sale of the property.
By purchasing the property from trustees, under Section 2 of the Law of Property Act 1925, the occupation rights of any other party are automatically extinguished. If such a party claims an overriding interest in the land, that interest is converted by attaching a monetary interest to the land - eg a purchase price, and the interest claimed by the party is 'overreached', this conversion is often referred to as the doctrine of Equitable conversion.
If only one owner exists, then there is a risk that a third party could claim occupation, and overreaching cannot apply.
The issues of overreaching and overriding interests are often closely linked, and the case of Birmingham Midshires v Sabherwal[1] examined both issues.