Overview

Changes the billing frequency on a bound policy. This reschedules all pending invoices to match the new frequency, archives the old invoices, reallocates any existing payments, and optionally recalculates installment fees.

What this endpoint does:

1. Loads the policy by policyID
2. Validates the frequency change is allowed (permission, dates, existing payment state, valid frequency)
3. Archives all pending invoices and deallocates payments
4. Creates new invoices on the new billing schedule
5. Reallocates any previously allocated payments
6. Recalculates installment fees if the rating program uses per-installment fees
7. Updates pending endorsements and book/page policy schedules if applicable
8. Fires a BillingFrequencyChanged event

Preconditions: User must have Edit (Policy) and Create (MemberTransaction) permissions. New frequency must differ from current. Transaction date must be before expiry. Pending bills must exist. For account-level billing, pending invoices must not have allocated payments.

Side effects: Archives old invoices, creates new schedule, reallocates payments, recalculates fees if applicable, updates pending endorsements and PEL structures, fires BillingFrequencyChanged event.

Returns: RequestMethodResponse with IsSuccessful = true and RecordID = the policyID.