In land ownership, general boundaries (the norm in registered title) do not seek to define boundaries precisely but are an aspect of land ownership where the position on the ground may prevail over the line drawn on a plan.

These were the helpful and succinct comments of Lord Briggs in the Supreme Court ruling in Brown v Ridley [2025] UKSC 7 - the most defining decision on adverse possession for many years. It clarified the 10-year requirement for ‘reasonable belief’ of ownership of a contested piece of land.

A person can seek legal ownership over another owner’s registered land by adverse possession under the Land Registration Act 2002 if specific conditions are met. In Brown v Ridley, Mr and Mrs Ridley claimed adverse possession of a neighbouring strip of land. The Ridleys bought their property in 2004 and their neighbour, Mr Brown, had bought his property in September 2002.

However, the previous owner of the Ridley’s property had put up a fence and a hedge along what he mistakenly believed was the boundary - but it wasn’t until October 2019 that a dispute arose. The Ridleys were planning to build a new house and Mr Brown served notice on them stating that the planned construction breached the Party Wall Act.

The Ridleys then made their application to be registered as legal owners of the disputed strip of land. The First-Tier Tribunal found that the Ridleys had a reasonable belief they owned the disputed land until February 2018 (around 21 months before their application). The key issue centred around the meaning of the statutory 10-year period under paragraph 5(4) Sch 6 which states:

“for at least ten years of the period of adverse possession ending on the date of the application, the applicant (or any predecessor in title) reasonably believed that the land to which the application relates belonged to him…”

The Supreme Court considered whether the 10-year period of reasonable belief must be the 10 years prior to the application or any10 years within the claimant’s period of adverse possession. It concluded that Parliament’s intention was the latter: any 10-year period of reasonable belief was sufficient.

If the alternative, narrower construction was correct, an applicant for adverse possession would have to make an immediate application when their reasonable belief ended – an unrealistic and unattractive expectation. Further, it would lead to more neighbour disputes and effectively prevent early mediation or other forms of ADR. Lord Briggs noted the general “potential for disputes about boundaries to generate disproportionate cost, effort, dismay and hatred if litigated”.

The SC’s decision meant the Ridleys could be registered with legal title to the dispute strip of land – restoring the decision of the First Tier Tribunal. The judgment provides important analysis of the legal framework for adverse possession and guidance for future claims based on 10 years’ ownership.

Finally, a procedural point: practitioners should note that HM Land Registry has updated Practice Guide 5, impacting first registration of leasehold land gained through adverse possession where the lease is unregistered.

Speaker David Keighley is covering this topic and more at our upcoming LAW2026 events. Discover our upcoming events here.