Delinquency & fees

When an installment isn't paid by its due date, the loan moves out of "current" and starts accruing penalties. The background servicing sweep (on the admin worker) drives this every day.

Servicing status & delinquency buckets

A loan carries a servicing status — Current, In arrears, Overdue, In collection, Restructured, or Frozen — and, once past due, a delinquency bucket by age:

Bucket	Age of the oldest unpaid amount
Current	not past due
1–30 days	up to a month overdue
31–60 days	one to two months
61–90 days	two to three months
90+ days	more than three months

The aging sweep recomputes the bucket each day from the oldest open installment; paying the arrears down moves the loan back toward Current (a cure).

Late fees

A product can charge a recurring late fee while a loan is in arrears:

• LateFeeAmount — the flat amount charged each interval.
• LateFeeInterval — how often it recurs: daily, weekly, or monthly.

The sweep raises a late-fee charge on the loan for each elapsed interval; it collects through the normal waterfall like any other fee.

Default interest

Overdue balances accrue default interest — a penalty rate on top of the loan's ordinary interest:

• DefaultInterestRatePercent on the product sets the penalty rate.
• It accrues value-dated on the overdue amount from the date it fell due, so the penalty is reproducible as of any date rather than a stored running number.
• It's the first bucket in the waterfall, so an incoming payment clears the penalty before ordinary interest, fees, or principal.

Because everything is value-dated and append-only, a loan can be recalculated (re-termed) mid-collection and a payment that lands afterward still applies correctly — the balance always nets out.