Explainer ยท Schedule Engine

Prepaids, Accruals, and Amortisation:
A Controller's Guide to Automated Schedules

D
Daniel O.
Controller, Multi-Entity
Jan 28, 2026 ยท 7 min read
โ† Back to Journal

Manual roll-forwards in spreadsheets are the number one source of close errors.

Why? Because spreadsheets remember nothing.


What Goes Wrong in Manual Schedules

  • Incorrect opening balances
  • Hard-coded formulas
  • Broken links
  • Missed reversals
  • Inconsistent amortisation logic

"And worst of all: no audit trail of change. Every edit is invisible. Every correction is untraceable."


How an Automated Schedule Engine Should Work

There are five non-negotiable properties of a production-grade schedule engine:

1

Transaction-Level Source of Truth

Every schedule item should be tied to an invoice or JE, start date, end date, total amount, and amortisation logic. No manual opening balance inputs.

2

Deterministic Amortisation Rules

Rules should be visible and version-controlled. Examples: straight-line monthly, daily pro-rata, custom term-based allocation.

3

Auto-Generated Journal Entries

At period close: expense recognition posted automatically, reversals scheduled correctly, no manual recalculation required.

4

Rollforward View Built-In

Every schedule should show: Opening balance + Additions โ€“ Amortisation = Closing balance. With full drilldown to the source transaction.

5

Audit-Ready Change Log

If someone edits a term, amount, or start date โ€” the system must log who changed it, when, and why. No silent edits.


The Rollforward Anatomy

Prepaid Insurance โ€” Q1 2026
Opening balance: $48,000
+ Additions: $12,000
โ€“ Amortisation: ($15,000)
= Closing balance: $45,000

Every line drills to the source. Every movement is explained. No plugs. No "balancing entries."


"Automated schedules don't just save time. They eliminate structural risk โ€” the kind that shows up as a material weakness."

Lunari Schedule Engine

Replace your spreadsheet roll-forwards.

Prepaids, accruals, fixed assets, loans โ€” all automated, all audit-ready, all tied to source transactions.