The BoE predicted inflation will rise to more than 13% in the coming months.
Citi's forecast - which would be the UK's highest rate of inflation since 1976 - comes ahead of Friday's energy price cap announcement on the maximum amount suppliers can charge households for gas and electricity from October.
The investment bank's forecast is at the higher end of the scale compared to those made by other economists, such as EY-Parthenon which has forecast inflation to be at 15.4%.
