Medallion Signature Guarantee The Medallion Guarantee or a Medallion Signature Guarantee Stamp is a special stamp. This stamp is applied to a stock transfer form that indemnifies the transfer agent against any fraudulent transfer. Once applied, it tells the transfer agent that the transaction is genuine and that the person who signed the form has the legal authority to carry out the transfer. Apostille & Legalisation Services Ltd offers Medallion Signature Guarantee (£220 plus VAT per Stamp /Stock) We have partnered with IWC Estate Planning & Management Ltd to supply a full Medallion Signature Guarantee Service. IWC offers complete securities, stock transfer, and sale services. https://www.apostille-services.co.uk/medallion-signature-guarantee/