Examines the new regime introduced by the Land Registration Act 2002 to govern the operation of adverse possession over registered land. This strengthens the protection afforded to the registered proprietor by limiting any claim that can be made by squatters, who now have the right to apply for registration as registered proprietors after a minimum of 10 years. The Act highlights the role of the claimant's mistaken belief and the defendant's acquiescence in the operation of estoppel. Explores the operation of estoppel in the context of adverse possession under the Act by focusing on the overlap between the two doctrines, which may operate in similar circumstances. Concludes that the policy of the Act is clear: adverse possession and registration of title are incompatible save in the rare cases where the greater injustice is caused by disturbing the squatter than in protecting the registered owner.