To find a missing heir abroad, you will need to hire a professional probate genealogist or an heir hunter with a proven track record in international cases. These professionals can access specialised databases and open-source intelligence and use DNA genealogy and public records to track down the beneficiary. Professional help is also needed for local knowledge and to navigate language barriers and foreign data policies.
Many heir-tracing companies don’t charge unless they are successful, but it’s always wise to ensure that you agree on a fee from the outset, so you can budget accordingly. If the heir isn’t able to be located, UK inheritance goes through a legal process and may ultimately become property of the Crown.