What is a CAM true-up and why does it get billed wrong?

A CAM true-up is the year-end reconciliation payment that settles the difference between what you paid in monthly estimates and what you actually owed based on final operating expenses. Errors occur most commonly when landlords compute the balance manually in a spreadsheet outside the property management system, introducing incorrect pro-rata percentages, stale estimate totals, or simple arithmetic mistakes.

What inputs does CAMAudit's true-up detection rule require?

CAMAudit's true-up detection rule requires three inputs: the total building operating expenses from the reconciliation statement, the tenant pro-rata share from the lease, and the cumulative monthly estimates paid throughout the year. If the reconciliation statement does not include the estimate total, the tenant's own payment records or accounts payable ledger can supply that figure.

How does the tolerance work in the true-up calculation?

The tolerance is the greater of $50 or 0.5% of the tenant's share of actual expenses. This prevents the true-up detection rule from flagging rounding differences between the landlord's software and CAMAudit's calculation. Only amounts above the tolerance are flagged as overcharges requiring dispute.

Can the true-up work in the other direction, where the landlord owes me a refund?

Yes. If your cumulative monthly estimates exceeded your actual share of building expenses, the landlord owes you a credit. The same formula applies: if the expected true-up is negative, meaning you overpaid through your monthly estimates, the landlord should issue a credit rather than a balance due. Review your reconciliation for a credit line if your estimates appear higher than the final expense allocation.

Math-Based Rule

Estimated Payment True-Up Error: When the Year-End Balance Due Is Wrong by Thousands

Angel Campa, FounderCAMAudit

Last updated: April 2026

If your landlord's year-end reconciliation 'Balance Due' is higher than the difference between your actual CAM share and what you paid in monthly estimates, you're being overcharged. For a tenant paying $3,000/month in estimates, even a $3,200 arithmetic error on a single true-up is money that was never owed.

Definition

Estimated Payment True-Up Error

An estimated payment true-up error occurs when the year-end reconciliation balance billed by the landlord exceeds the mathematically correct true-up amount. The correct true-up is calculated by taking the tenant's actual share of total building operating expenses for the year, which equals the total building expenses multiplied by the tenant's pro-rata share percentage, and subtracting the cumulative monthly CAM estimates the tenant already paid throughout that year. Any amount billed above that difference, after applying a rounding tolerance, is an arithmetic overcharge. These errors occur most often when landlords compute the year-end balance in a spreadsheet separate from their property management system, introducing stale estimate totals, wrong pro-rata percentages, or simple arithmetic mistakes. CAMAudit's true-up detection rule extracts all three required inputs from the uploaded documents and performs the correct calculation, then compares it to the billed Balance Due to identify any overage.

How CAMAudit Detects This

CAMAudit extracts the landlord's billed true-up amount from the reconciliation statement, specifically the line labeled 'Balance Due,' 'Year-End Adjustment,' or a similar designation. CAMAudit identifies this figure as the starting point for the arithmetic verification.

CAMAudit's true-up detection rule calculates the expected true-up using three inputs extracted from the uploaded documents: the total building operating expenses from the reconciliation statement, the tenant pro-rata share from the lease, and the cumulative monthly estimates the tenant paid throughout the year. CAMAudit multiplies the building total by the pro-rata share to derive the actual tenant obligation, then subtracts the estimates paid.

CAMAudit flags the finding as an overcharge when the billed true-up exceeds the calculated expected true-up by more than the tolerance, which is the greater of $50 or 0.5% of the tenant share of actual expenses. CAMAudit reports the exact dollar difference between what was billed and what was owed so you can present the specific arithmetic in a dispute.

Real-World Example

Charleston County, SC government leases office space managed by Thalhimer as property management agent. Public A/P records show the county wired a $41,283.76 CAM reconciliation payment in March 2019. In the fixture scenario: building total operating expenses of $412,837.60, tenant at 10% pro-rata share, actual tenant share of $41,283.76, monthly estimates paid of $3,000 times 12 equals $36,000. Correct true-up: $5,283.76. Landlord billed: $8,500.00. CAMAudit flagged the $3,216.24 overcharge.

Free scan · No account required

Upload your lease. CAMAudit runs 14 detection rules in under 15 minutes.

Scan My Lease Now

See a sample report first

Frequently asked questions

Free scan · No account required

Find overcharges in your CAM reconciliation. Most audits complete in under 15 minutes.

Scan My Lease Now See a sample report first

Explore Related Resources

Concept ComparisonFixed CAM vs Variable CAM Concept ComparisonEstimated vs Actual CAM Charges CAM Line ItemProperty Management Fee CAM Line ItemCommon Area Insurance Lease ClauseAudit Rights Clause Lease ClauseBase Year Stop Clause

Next Best Step

This rule is evidence, not the end of the journey

Use the rule page to understand the issue, then move back into the proof sequence and the audit flow.

Read your free results

See how triggered findings appear before payment.

Unlock your report

Review what unlocks, pricing, and the dispute-ready output.

Start Free Audit

Upload your lease and reconciliation to document the overcharge.

Ready to skip the reading and document the overcharge directly?

Find My Overcharges

Related Resources

Lease ClauseAudit Rights Clause Lease ClauseBase Year Stop Clause ScenarioI pay percentage rent and suspect the breakpoint is wrong ScenarioI received a credit memo but the amount seems too low ResourcesCAM Line Items Guide ResourcesTenant Type Guides ToolsFree CAM Audit Tools

Need to extract lease terms before your audit?

A CAM audit is only as accurate as your lease data. lextract.io extracts 126 structured fields from any commercial lease PDF: CAM definitions, pro-rata share, caps, base year, and audit rights. So you have the exact terms your landlord is supposed to follow.

Go to lextract.io

This page provides general educational information. It is not legal advice and may not reflect the most current law in your state. Consult a licensed attorney for advice specific to your situation.

Estimated Payment True-Up Error: When the Year-End Balance Due Is Wrong by Thousands

Angel Campa, FounderCAMAudit

Last updated: April 2026

How CAMAudit Detects This

Real-World Example

Free scan · No account required

Upload your lease. CAMAudit runs 14 detection rules in under 15 minutes.

Scan My Lease Now

See a sample report first

Frequently asked questions

Free scan · No account required

Find overcharges in your CAM reconciliation. Most audits complete in under 15 minutes.

Scan My Lease Now See a sample report first

Need to extract lease terms before your audit?

Go to lextract.io

This page provides general educational information. It is not legal advice and may not reflect the most current law in your state. Consult a licensed attorney for advice specific to your situation.