When it comes to unregistered land, legal rights bind the world whereas equitable rights are binding on everyone except the bona fide purchaser of a legal estate for value without notice.

The concept of notice has become much more rationalised since the Law of Property Act 1925 and the Land Charges Act 1925 as amended by the Land Charges Act 1972.There are a number of interests that can be registered as charges:
A: Rights arising under a statute upon application
B: Rights arising under a statute automatically
C: (i) Puisine mortgages
(ii) Limited Owner’s Charge
(iii) General Equitable Charge
(iv) Estate contracts (contracts for transferring the legal estate, options to purchase, rights of pre-emption)
D: (i) Inland Revenue charges
(ii) Restrictive covenants
(iii) Equitable easements
E: Annuities created before 1926
F: Protection of home rights under the Family Law Act 1996
Failure to register the interest means that the right is lost although there are exceptions for classes C(iv) and D where failure to register means the right is lost unless dealing with “a purchaser for money or money’s worth of a legal estate in the land charged”.
The land charge system makes the law much more certain and means that equitable interests that do not fall under a defined class are very limited indeed: Caunce v Caunce [1969].