Can an executor hire a professional heir-tracing firm, and who pays for that search?

Yes - an estate trustee can hire a professional heir-tracing (genealogical research) firm to help locate missing beneficiaries or unknown next of kin. Doing so is a common, reasonable step when a will names someone whose whereabouts are unknown, or when an intestacy requires figuring out who the eligible heirs actually are in the first place.

The cost is normally paid out of the estate itself, as a reasonable expense of administration, rather than out of the executor's own pocket. Many heir-tracing firms work on a contingency basis, taking a percentage of a found heir's share instead of charging the estate directly - an arrangement that should be reviewed carefully, since the estate trustee still has a fiduciary duty to ensure the fee is reasonable given the difficulty of the search.

Before hiring a firm, an estate trustee should keep records showing why the search was needed and what alternatives, such as family contacts, obituaries, and prior court filings, were tried first, since a court reviewing the trustee's accounts may ask about the reasonableness of the expense. Getting legal advice before signing a contingency agreement with a tracing firm is worthwhile, because these agreements can vary widely in what they promise and what they charge.