Inheritance Tax Manual

IHTM30352 - Rates of interest: the rates

Detail on how the rates of interest for Inheritance Tax purposes are calculated can be found at IHTM30341. 

The statutory rates for charging and repaying supplementary interest since 6 October 1988 can be found on GOV.UK.  

(For reference purposes, the statutory rate from 16 December 1986 to 5 June 1987 was 8%, from 6 June 1987 to 5 August 1988 it was 6% and from 6 August 1988 to 5 October 1988 it was 8%.)