If an institution changes the Nominal annual interest on the savings product configuration in this change should be applied to already existing accounts created.
E.g if during savings product creation, MFI sets Nominal annual interest as 18% and after some time decided to change it 14% then I think this should not be applied to new accounts created after this change but rather cut across any other existing account on that product going forward (cause I have tried to update this from the database and it was messy, its updated all the existing account alright but recalculated the interest on the exiting account dating back to 2015 to date.).
The Savings product Nominal annual interest configuration should not be stored in the account table but rather a pointer can be set to them with effect from the date of input or a specific start to end date for a new calculation.
Please this very critical for the survival of a lot of MFIs due to the COVID-19 pandemic which has seen a lot of interest rates fall massively. Imagine having over 20,000,000 in a savings accounts from over 20,000 customers and paying 8% currently instead of 5% or 4 % that's over 600,000 to 800,000 in losses automatically.