How can you build an automated system to track commercial loan amortization and match it exactly to bank-calculated balances?

Because matching a bank's actual/360-day-count amortization schedule automatically is virtually impossible, the solution was to build a custom amortization calculator with a 'balance in time' ledger. This lets the system record a to-the-penny accurate balance and interest figure at year-end, backed by bank documentation, rather than trying to perfectly replicate the bank's calculation in real time — since even banks require a call for the actual payoff balance due to constantly running interest calculations. The system lets a user connect a loan to a bank account; once linked, pure data logic (no AI) detects incoming payments each month, locates them on the amortization schedule, and automatically applies the principal/interest split. It also maintains a double-entry-style liability account, debiting/crediting appropriately, with the ability to manually adjust recorded payments so the balance matches to the penny when preparing the year-end tax package.