A commercial real estate due diligence checklist covers six groups: title and survey, leases and tenants, financials, the physical building, environmental condition, and legal and zoning. For each one, ask for the documents, tie them out against each other, and write down what is missing before the contract deadline.
The checklist
1. Title and survey
- Title commitment and exceptions; recorded liens and mortgages
- Survey, easements and access
2. Leases and tenants
- Every lease and amendment; a rent roll that matches them
- Estoppel certificates from each tenant
- Options, escalations, termination rights, expiry dates
3. Financials
- Trailing twelve months (T-12), two to three prior years, and bank statements
- Tax bills, insurance, utilities, service contracts
4. Physical
- Property condition report; roof, structure, mechanical, parking
- Capital work done and planned
5. Environmental
6. Legal and zoning
- Zoning compliance, permits, open violations, pending litigation
The tie-outs that find problems
Most surprises appear between documents, not inside one. Compare:
- rent roll with leases;
- rent roll with T-12 income;
- T-12 with the offering memorandum;
- the tenants named with the tenants on record.
A worked example (hypothetical numbers)
A rent roll, annualized, shows 1,056,000 of rent. The T-12 shows 1,011,000 of rental income. The difference is 45,000, or 4.3% of the rent roll. It could be a vacancy that began mid-year, a concession, or rent the roll counts but nobody collected. The checklist step is to find out which, before the number reaches the model. The figures are invented for illustration.
What a checklist and software do not replace
A checklist does not replace the people who sign off: an attorney for title and leases, an engineer for the building, an environmental consultant for the site. Software reads and compares documents faster; it does not replace their opinions. Titleman names gaps instead of filling them, so a missing lease shows up as missing.
Read next: what AI underwriting is and AI due diligence coverage and gaps.
Common questions
How long is the due diligence period for a commercial property? It is set in the purchase contract, so it varies by deal. Thirty to sixty days is a common reference range, but the contract controls. Ask your attorney which items must be delivered by which day.
What is the first thing to check? Whether the income is real. Tie the rent roll to the T-12 and the T-12 to bank records. Everything later, from value to loan size, rests on that income figure.
What do buyers most often miss? The gaps between documents: a lease in the rent roll that is not in the file, an expense missing from the T-12, or a tenant with a termination option that the offering memorandum does not mention.
Can AI do due diligence? It can do the reading and the tie-outs, and name what is missing. Titleman reads the documents and the record on the property and flags gaps. Legal opinions, inspections and the decision stay with people.
Published by Titleman, which makes the AI engine mentioned on this page. Written by the Titleman team with AI assistance. Updated 19 October 2026.