A debt on a security must be marketable or at least have such characteristics to enable it to be dealt in and converted into shares or other securities. Aberdeen Construction Group Ltd v IRC 1978 STC 127
Loan notes which require the consent of the issuer for their transfer, and were redeemable at the option of the issuer before redemption, were held not to be debts on a security. Tarmac Roadstone Holdings Ltd v Williams 1996 SpC 409
Convertibility is sufficient to render the loan a debt on a security. Mooney v McSweeney 1997 V ITR 163
