10 Jan 2017 They are not therefore subject to capital gains tax (or, for companies, corporation tax). Paragraph 1 of 0⅛% Index-linked Treasury Gilt 2036. The rate can be fixed or linked to the retail prices index. Interest from gilts is savings income for the purposes of the income tax calculation, and so the The exemption does not normally apply to interest which is taxable as trading income. Other options are Index-linked gilts which track the Retail Price Index (RPI) or you All gilts and some corporate bonds are exempt from capital gains tax (CGT).