Nil Rate Band Escalation % - The UK inheritance tax threshold (the Nil Rate Band) is set at 325k through 2020, after which it will then increase in line with the Consumer Prices Index (CPI), per legislation.
In Voyant, the escalation rate for the Nil Rate Band from 2021 onwards is set based on the Nil Rate Band Escalation preference in the software's Plan Preferences (to the right side of the Preferences screen). This escalation rate is set separately form CPI on order to give you greater flexibility.
Plan Preferences vs. System Preferences
Changes to this setting on the mirror Default Inflation / Growth Rates panel in System Preferences, on the left side of the screen, will be used only going forward, as you create new client cases. System Preferences are used as a template only for new client cases. Changes to System Preferences will not retroactively affect your existing client cases.
If you want to change this preference in any existing client cases, you will need to open and edit them individually, in each case's Plan Preferences.