A petition for informal appointment in intestacy (without a will) must also attest that, after a reasonably diligent search, the petitioner is unaware of any unrevoked will or why such an instrument the petitioner is aware of is not being probated.

Source: https://businesswest.com/blog/representatives-must-navigate-the-many-ways-to-probate-an-estate/

“Moreover, the intestacy rules do not account for non-traditional family structures, stepchildren, unmarried partners, or close friends who may have been financially dependent on the deceased.

Source: https://worcesterobserver.co.uk/lifestyle/daniel-curran-finders-international-discusses-what-happens-to-an-estate-if-a-person-dies-intestate/

Unclaimed estates, classed as ‘ownerless property’, occur when there is no will – or the beneficiaries of the will cannot be traced - and the next family member, following the rules of intestacy, cannot be found.

Source: https://www.coventrytelegraph.net/news/coventry-news/thousands-pounds-inheritance-limbo-amid-26918555