Audit a sponsor's underwriting model and deal documents in Claude for Excel before you invest
At a live PLOT and Thesis Driven workshop, Claude's Excel integration reviewed a general partner's multifamily model that showed a limited partner IRR near 440%. Claude found insurance listed in the model but left out of operating expenses, first-year revenue built on market rents instead of in-place rents, and an exit cap rate below the going-in cap rate, and pointed to the specific cells behind each issue. In a second exercise, Claude compared an offering memorandum, rent roll, and T-12, found two units with conflicting occupancy worth about $23,000 in annual scheduled rent, and wrote questions for the broker instead of guessing. The workshop did not produce a verified corrected IRR, so an analyst still checks every flag.
At a glance
- Tools used
- ClaudeExcel
- Category
- Investing & underwriting
- Audience
- investor
- Difficulty
- Copy-paste
- Source
- How Claude Catches Major Errors in CRE Underwriting
PLOT Daily Editorial Desk · Article · Oct 15, 2026 - First step
- Open the sponsor's underwriting workbook in Excel with the Claude add-in, keep the offering memorandum and the stated investment terms at hand, and paste the audit prompt below before you look at the returns tab.
Compliance note: Treat every flag as a question to investigate, not a conclusion; an unusual figure, such as low property taxes, can have a legitimate explanation. The source notes that Anthropic cautions against using Claude for Excel for final client deliverables or audit-critical calculations without human review, so have an analyst verify each finding before an investment decision.
Suggested prompt
Written by this directory, inspired by the source. Replace the [bracketed] parts.
Audit this underwriting workbook against the offering memorandum and the stated investment terms I attached. Use only the figures in these documents. 1. Check for mechanical formula errors and broken links between tabs. 2. Find any expense that appears in the model but is missing from the operating expense total, or that is counted twice. 3. Check whether first-year revenue uses in-place rents from the rent roll or market rents, and flag any gap. 4. Compare the exit cap rate with the going-in cap rate and flag aggressive exit or growth assumptions. 5. Compare the offering memorandum, rent roll, and T-12 for conflicting unit occupancy, rents, or expenses, and flag any expense that looks unusually low for the property's revenue, such as real estate taxes. For each issue, give the sheet and cell, the dollar effect where you can calculate the dollar effect, and the source document. Do not fix the model or assume missing figures. End with a list of questions I should send the sponsor or broker.