The Amortisation Schedule determines how the Loan Balance reduces over time if all repayments are made on time (it is very similar to the outstanding principal balance that Mambu could calculate on its repayment schedule). The loan balance on the amortisation schedule is referred to as the Scheduled Balance of a loan. The Amortisation Schedule is not a payment schedule (see LNN-I-4).
Loans amortise (i.e. are expected to reduce in principal balance) with a monthly frequency which aligns with the interest capitalisation frequency (see DPS-I-9).
The amortisation schedule needs to be calculated based on the interest period type. DBEI in case of variable-interest-rate periods (indexed interest rate) and fixed-interest-rate periods. Or only expect interest from the borrower in case of interest-only periods. See comments below for details for these types of interest periods and LNN-I-6 for use cases for transitions between different types of interest periods.
Minimum Repayment Amount
This is common market practise in Australia. A separation between amortisation and repayment schedules is also a common approach in other markets.
Note - This requirement is more general but overlaps with APP-I-1214 (dynamic loans)