CPI (Consumer Price Index) and RPI (Retail Price Index) are default assumptions set on the software's Subscription Preferences screen by Subscription Managers.
These index assumptions can be edited for the client case at hand in the Plan Settings screen found at the bottom of the Dashboard, in the Default Inflation / Growth Rates panel.
While not displayed as an editable preference, LPI (Limited Price Indexation) is also available as an option in the final salary escalation selection and will be calculated as equal to RPI or 5%, whichever of the two is lower (i.e. with a maximum of 5%).
How are RPI, CPI and LPI used in Voyant?
The CPI preference is used to escalate the Residential Nil Rate Band (RNRB) and in the Real Money calculations.
These indexes can also be used (if selected) to inflate items such as escalating final salary and annuity payouts, when selected as an index on the Pensions > Final Salary or Annuity Basics screens.
The software's Real Money simulation (an option available on the Let's See charts and in Reports) displays present values of the calculation results using CPI to compute the present values.
Plan Settings vs. Subscription Preferences
Changes to these settings in the Default Inflation / Growth Rates panel in Subscription Preferences, on the left side of the screen, will be used only going forward, as you create new client cases. Subscription Preferences are used as a template only for new client cases. Changes to Subscription 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 Settings.
Further reading
How to set custom preferences (plan settings) for your subscription