Are they asking for any money upfront or only if successful?
There are quite a few firms of genealogists like this. I have had no dealings with this firm but the firm who I seem to come across mostly are Hoopers.
Providing this has come from Bond Lane research, it is not a scam.
These firms of genealogists research and scan obituaries and public notices looking for people who have died without any family and with no will.
Generally, these estates are then dealt with under the rule of intestacy and to avoid everything going to the Crown they find distant relatives. Sometimes, very distant.
They also look for missing relatives if there is a will.
It is highly likely that you would not even know who the relative is that has died. There is nothing to stop you ignoring this letter and looking for the deceased relative yourself. Then, you would get the full amount owing to you rather than losing 25% to pay their fee.
This is no win no fee in effect and if you get some money, you will be giving away 25% for the benefit of them having done the research and finding the relative and finding you.
They will not tell you who the relative is or how much you may inherit in very often, these matters can hang around for years. I have known clients in the situation who have inherited tens of pounds and others who have inherited hundreds of thousands of pounds.
These agreements are legally enforceable and if you sign it and then argue over the money later, they will take you to court and generally win.
My advice to clients is that provided you are happy with the provenance of the research genealogists, or carry out your own research. Clients usually just sign the document. There is no guarantee remember that you would ever find the person and hence, no guarantee you would ever get any money.
Can I clarify anything for you?