ST1 of deceased squatter

I would be grateful for your guidance on the correct approach to filling in a ST1 form in the following circumstances. My grandma and gramps owned a house and, from the 1980s onwards, also looked after and treated as their own an adjoining parcel of unregistered land which was not included in their title. Their occupation and use of this land continued uninterrupted until my gramps passed away during lockdown and my grandma in 2024. No application was made during their lifetimes to register this land by adverse possession. Under my grandma's will, her two daughters (my mam and my aunt) were both named as executors. Probate was granted with my aunt as the active executor and my mam as an executor with power reserved. Following the grant of probate, I purchased my grandma and gramps's house last year which is now registered in my name and have since continued to look after the adjacent land. I now wish to apply to register that additional land based on their prior adverse possession. We have photos showing their maintenance of the land going back many years, but as my grandma and gramps are no longer with us, they are unable to complete the ST1 form. My mam, despite having executorial power reserved, is best placed to give evidence of the relevant facts as she lived on the same street, visited daily and was closely involved in the maintenance and use of the land over many years. By contrast, my aunt, although named as the active executor in the grant of probate, had significantly less direct involvement and knowledge of the factual history. The ST1 guidance refers to enclosing supporting documentation such as an office copy of the grant of probate when making a statement on behalf of the deceased. Given that my mam is their daughter and an executor with power reserved under the grant of probate, does she have the necessary standing to complete the ST1 on behalf of my grandma and gramps based on her personal knowledge of the facts, or does only the active executor have the authority to fill in the form on behalf of the deceased, notwithstanding their more limited knowledge of the circumstances? Any guidance on who should complete the ST1 would be greatly appreciated.

Smaley I - a statement of truth can only be completed by a living person. Whilst their next of kin than refer to what their (grand)parents did or did not do it is invariably only their own facts re occupation/possession that will be considered. The ST1 guidance refers to supporting documentation such as a probate where the declarant has made their own statement but then passed away Adverse possession is a very complex area of the law and it is strongly recommend that you seek legal advice as a result. The legal requirements come first and we can't advise you on how the law would view such a claim. The registration requirements come second and a key tenet is that the claim meets all the legal requirements before registration can proceed

Thank you, so if my mam completes the ST1 based on her own factual knowledge, how should she answer the tick boxes in panel 2?

She can still complete the ST1 with the facts as she knows then and who she is making the statements on behalf, namely the deceased. But you need to take due regard with the legal requirements (legal advice) and then the registration ones (PGs 4 and 5 as appropriate). The legal advice will help you/her understand whether a legal claim exists and if so what 'facts' support that https://www.gov.uk/government/collections/land-registration-practice-guides#guides-1-to-10