Automating index and escalation calculations in commercial leasing
The Planyum Team · October 9, 2026
Residential leasing is simple: a fixed rent, a fixed date. Commercial and institutional leasing is different. In a shopping center, office, or mixed-use project, rent is often tied to an index, sometimes to a percentage of turnover, sometimes to a combination of both. When these calculations are done by hand in a spreadsheet, the margin for error becomes a real risk.
Index escalation isn't a one-time task.
If a lease is tied to an annual inflation index, someone has to make sure the correct index value is applied at every update cycle; across a large portfolio of leases, that's far too repetitive a task to track manually.
Revenue-based rent adds another layer of complexity.
Making sure the tenant's declared turnover matches the formula in the contract requires transparency on both sides; how the calculation is done needs to be visible, not just the result.
Late-payment interest should be rule-bound too, not person-bound.
When a payment is late, the rate and the date it starts accruing from should be defined in advance; otherwise every late payment turns into its own negotiation.
This transparency matters especially for institutional investors and international advisory firms.
For a structure managing a portfolio across multiple countries or currencies, being able to trace which rule updated which contract is the foundation of reporting and audit processes.
Planyum's Commercial Lease Rule Engine automates all of these calculations on a formula basis, including subtenant structures, and keeps every calculation traceable back to the rule it was built on.