Payment schedule and GL posting

The model

For every IFRS 16-capitalised lease, Shillinq materialises one LeasePaymentSchedule row per payment period. The row is computed by the pure-logic LeaseAmortizationCalculator (cents-only arithmetic, no IEEE-754 drift) so the same numbers are reproducible from the lease contract alone.

Every row carries:

Field	Meaning
periodSequence	1, 2, 3, …
periodStart / periodEnd	ISO dates derived from commencementDate + frequency.
openingLeaseLiability	The liability at the start of the period.
paymentAppliedTotal	The contractual payment for the period.
interestAccrued	openingLiability × periodicRate (IBR / periodsPerYear).
paymentPrincipalPortion	paymentAppliedTotal − interestAccrued.
closingLeaseLiability	openingLeaseLiability + interestAccrued − paymentAppliedTotal.
depreciationCharge	Straight-line over the term of the RoU asset.
postedToGl	FK to the GL transaction (filled by period-close, immutable thereafter).

The closing liability of the final period is forced to exactly zero — the calculator absorbs any rounding into that row's principal so the schedule lands cleanly.

What hits the GL

For each period the period-close engine posts:

Dr. Interest expense              <interestAccrued>
   Cr. Lease liability               <interestAccrued>

Dr. Lease liability               <paymentPrincipalPortion>
   Cr. Bank                          <paymentPrincipalPortion>
  (payment leg goes through the bank reconciliation)

Dr. Depreciation                  <depreciationCharge>
   Cr. Accumulated depreciation      <depreciationCharge>

Every line carries sourceLease=<lease-id> so the audit trail can be walked end-to-end (ADR-022).

Preview

The Lease Detail page shows the next 12 months of the schedule inline; the full set is downloadable via the Audit pack action (see Disclosures).

Regeneration

If the lease's economics change (extension reassessment, indexation, modification), LeasePaymentScheduleService::generateSchedule(leaseId, administrationId, fromSequence) regenerates rows from fromSequence forward. Existing posted rows are protected by the immutability rule on LeasePaymentSchedule — only future periods are overwritten.

Notes

• Schedule generation skips exempt and out-of-scope leases (no rows).
• The schedule is administration-scoped via the lease contract; cross-administration reads are blocked at the service layer (ADR-005 IDOR safety).
• The payment frequency choices map to fixed periods-per-year (monthly=12, quarterly=4, annual=1); irregular schedules fall back to monthly cadence and adjust per-period payments at activation.