Thanks for your question.
If the land in question is unregistered then you must have been using it continuously for 12 years in order to claim possession of it and be registered as the registered proprietor at the Land Registry
If the land is registered then you need only have been using it continuously for 10 years in order to apply for adverse possession at the Land Registry. Notice of the application will be sent to the current registered proprietor of the land (it will be picked up by whoever is administering the owners estate), who is obviously at liberty to object. It is therefore more difficult to claim adverse possession of land that is registered.
If you do not know whether the land is registered then you can check using the Land Registry's online service by downloading a copy of the register of the title (if any) for the property:-
If this does not illicit results then you should send a index map search to the Land Registry by using Form SIM (enclosing a map of the area), they will then tell you definitively if it is registered. You can also download that form from the LR website.
In the case of both applications you would have to submit form ADV1 to the Land Registry together with sworn statutory declarations regarding how long you have been using the land (from you and others who know of your use) and it may be something over which you should consider taking specific legal advice from a local solicitor to ensure that the application and supporting documentation is drafted correctly.
If you worked on the land with the permission of the owner on some kind of informal licence type basis then this period would not count towards the qualifying period for adverse possession. Adverse possesoin is what is commonly termed squatter's rights so any contractual occupation of the land does not fit with this form of application.
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