Sorting out a loved one’s estate is rarely simple, and it can throw up surprises even when you think you’ve seen every document in the file. One that catches a lot of families out is discovering a shareholding with a US brokerage or transfer agent — and being told that before anything can be sold or transferred, they’ll need something called a Medallion Signature Guarantee, or ‘medallion stamp’.
It comes at a difficult time to be dealing with extra paperwork. UK probate is already taking longer than it used to: the number of cases stretching to 21–23 months has risen by 131% since 2021, and incomplete or inaccurate paperwork is now the single biggest reason applications get held up. Add in an overseas asset like US shares, and there’s real potential for a straightforward inheritance to drag on for months longer than it needs to.
A Medallion Signature Guarantee isn’t the same as a standard notarisation. It’s a formal certification, provided only by a small number of authorised guarantor institutions, confirming that the person signing a share transfer is genuinely who they say they are and has the legal authority to do so. Crucially, the guarantor institution takes on liability if the signature later turns out to be forged — which is exactly why US financial institutions insist on it for transfers, estate distributions and letters of transmittal.
Because so few UK firms are authorised to provide this stamp, getting it right the first time matters. An incorrectly completed or improperly witnessed guarantee can be rejected by the US institution, sending the whole process back to square one and adding weeks to a probate timeline that may already be under strain.
If you’ve come across a US shareholding while administering an estate and aren’t sure what to do next, it’s worth speaking to specialists who handle this every day. Fraser and Fraser’s Medallion Signature Guarantee service is one of the few in the UK authorised to issue the stamp, for transactions of up to $1,000,000 — find out more at medallionsignature.co.uk/.
