STSM064010 | Bearer Instruments: Bearer Instrument duty - exemptions: Foreign loan securities
From HM Revenue & Customs · Stamp Taxes on Shares Manual
By virtue of FA99/SCH15/PARA13, there is no 1.5 per cent stamp duty charge on a bearer instrument that is issued outside of the United Kingdom (UK) in respect of a loan that is expressed in a currency other than sterling, and which is not:
offered for subscription in the UK, or
offered for subscription with a view to an offer for sale in the UK of securities in respect of the loan.