What Due Diligence Should Investors Complete Before Closing?

Dec 31, 2026 · By Oanh Nguyen · Broker & Loan Officer · Investing

When you buy an investment property, the time between an accepted offer and closing is your chance to confirm that the property is what you think it is. That's due diligence.

It's not just a home inspection. For a rental, you're also checking title, leases, rent records, permits, insurance, expenses and whether your plan still works once you see the real numbers.

Skipping steps here is one of the most expensive mistakes an investor can make. Once you remove your contingencies and close, many problems become yours.

In this post, I'll give you a structured due diligence checklist for investment properties: inspection, title, leases, permits, rent comps, insurance, expenses and your exit plan.

This is general information, not legal, tax or investment advice. Your purchase contract sets your contingency periods and rights. For legal questions, talk with a real estate attorney. For tax questions, talk with your CPA.

Know Your Timeline First

Due diligence happens inside the contingency periods in your contract. Common ones include:

• Investigation (inspection) contingency.
• Appraisal contingency, if financing.
• Loan contingency, if financing.
• Review of documents, like leases, HOA documents and the preliminary title report.

Write down every deadline the day your offer is accepted. Schedule inspections immediately. If something needs more time, talk with your agent early about options.

1. Physical Condition: Inspections

Start with the property itself.

• General home inspection for each unit and the building.
• Wood-destroying pest inspection.
• Roof inspection.
• Sewer lateral camera inspection.
• Specialists as recommended: foundation, electrical, plumbing, HVAC, chimney, drainage, pool.
• Unit-by-unit access: in an occupied rental, coordinate entry with the seller and tenants, with proper notice under California law.

Then:

• Get written repair estimates from licensed contractors. Check licenses through the Contractors State License Board.
• Build a system-age inventory for the roof, water heaters, HVAC, panel and plumbing. My post on budgeting for repairs and capital expenditures explains how.
• Decide whether to ask for repairs, credits or a price change, or whether the property still fits your plan.

2. Title and Ownership

Review the preliminary title report carefully, with your title officer or attorney if needed.

Look for:

• Who holds title, and whether that matches the seller.
• Liens: mortgages, tax liens, judgments, mechanic's liens.
• Easements: utility, access or shared driveway rights.
• CC&Rs and restrictions, including HOA rules on rentals.
• Encroachments or boundary questions.
• Any recorded notices from the city or county.

Ask your title officer about anything you don't understand.

3. Leases and Tenant Records

If the property is occupied, you're buying the tenants' leases along with it.

Request and review:

• Every current lease and amendment.
• A rent roll: unit, tenant, rent, deposit, lease start and end dates.
• Rent payment history, to see who pays on time.
• Security deposit records. Deposits typically transfer to the buyer at closing. California Civil Code section 1950.5 governs security deposits.
• Any side agreements, like parking, storage or pets.
• Any notices given to or received from tenants.
• Estoppel certificates, if your contract and the leases allow. These are tenant-signed statements confirming lease terms and deposits.

Compare the rent roll with the leases and bank deposits. Differences are a red flag.

Remember the rules. State and local tenant protections stay with the property. The California Attorney General explains statewide rent rules. Cities like San José and Hayward have their own programs. Talk with a real estate attorney about how they apply.

4. Permits and Legal Use

Confirm the property's legal use and the permit history.

• Number of legal units. Does it match what's being marketed and rented?
• ADUs and conversions: permitted and finaled?
• Additions and remodels: permitted?
• Open or expired permits.
• Code enforcement history.
• Rental registration, if the city requires it.

Your city's building and planning departments can help you look up records. Unpermitted units or work can affect value, insurance, financing and how you can rent.

5. Rent Comps and Income

Don't rely on projected rents in a listing. Verify.

• Current comparable rents for similar units nearby.
• How fast similar units are renting.
• Whether current rents are below market, and what state and local rules say about increases.
• Other income: parking, laundry, storage. Can you verify it?

Build income from actual leases first, then think about any realistic changes within the rules.

6. Insurance

Insurance has become harder and more expensive for some California properties. Get quotes early in escrow, not the week before closing.

• Ask your insurance agent for quotes on a landlord or dwelling fire policy.
• Ask about liability, loss of rents coverage, earthquake and flood options.
• Check hazard information, like FEMA flood maps and California earthquake zone maps, and review the Natural Hazard Disclosure report.
• Confirm insurability before you remove contingencies.

The California Department of Insurance publishes consumer guides on residential insurance.

7. Expenses

Rebuild the property's expenses with real numbers.

• Property taxes: estimate based on your purchase price, not the seller's current bill. California generally reassesses property at sale. The State Board of Equalization's Publication 29 explains this.
• Insurance: from your actual quotes.
• Utilities the owner pays: ask for recent bills.
• HOA dues and any assessments, if applicable.
• Repairs and maintenance: from the seller's records and your inspections.
• Property management: even if you plan to self-manage.
• Reserves for replacements.
• Vacancy: a realistic assumption. My post on how vacancy rates affect cash flow explains how to choose one.

8. Financing and Appraisal

If you're financing:

• Stay in close contact with your lender about documents and timing.
• Review your Loan Estimate and compare it with what you expected. The CFPB explains each section.
• Watch the appraisal. A low appraisal can affect your loan amount and your plan.
• Understand how the lender treats rental income for your loan program. Guidelines vary, and the lender decides.
• Confirm cash to close and reserves.

Loan terms always depend on lender review and approval.

9. Your Exit Plan

Before you close, ask: How would I get out if I needed to?

• Sell to an owner-occupant? Is the property attractive to them, with or without tenants?
• Sell to another investor? Will the numbers work for them?
• Refinance later? What would need to be true?
• Hold long-term? Do you have the reserves and patience?

An exit plan protects you if your goals or the market change.

Extra Steps for Condos and Townhomes

If the property is in an HOA, add these to your list:

• Review the HOA disclosure packet: governing documents, budget, reserves, financial statements and insurance summary. California Civil Code section 4525 lists the documents sellers provide.
• Check rental rules: whether rentals are allowed, any caps on the number of rented units and minimum lease terms.
• Ask about special assessments, approved or under discussion.
• Read recent board minutes, if available, for planned projects or disputes.
• Confirm what the dues cover, like water, trash, exterior maintenance and insurance.
• Ask whether the project is approved for the loan type you're using, if financing.

An HOA that doesn't allow rentals, or limits them, can change your entire plan. Check before you remove contingencies.

Organize a Due Diligence File

Keep everything in one place, organized by topic. A simple folder structure works:

1. Contract and deadlines.
2. Inspections and estimates.
3. Title report and documents.
4. Leases, rent roll and deposit records.
5. Permits and city records.
6. Insurance quotes.
7. Expense records and your updated analysis.
8. Lender documents.

This file helps you make decisions now, answer questions from your lender and CPA and, someday, sell the property with organized records.

10. Final Review Before Removing Contingencies

Pull everything together:

Then update your analysis: cap rate, cash flow after the mortgage and cash-on-cash return. If the deal no longer works, talk with your agent about your options while contingencies are still in place.

Questions to Ask the Seller

1. Can you provide all leases, the rent roll and deposit records?
2. Are there any disputes or notices with tenants?
3. What repairs have been made, and by whom?
4. Were any units or additions built without permits?
5. Can you provide recent utility bills and expense records?
6. Has the property had any insurance claims?

Common Due Diligence Mistakes

1. Waiting to schedule inspections.
2. Trusting the listing's numbers without verifying.
3. Skipping the sewer lateral inspection.
4. Not reading every lease.
5. Getting insurance quotes too late.
6. Using the seller's property tax bill.
7. Removing contingencies before reviewing everything.

Key Takeaways

• Due diligence is more than an inspection for rentals.
• Verify leases, rents and deposits against records.
• Confirm permits and legal unit count.
• Get insurance quotes early.
• Rebuild expenses and update your numbers before removing contingencies.

A Hypothetical Example

This example is made up to show the process. It is not based on any real property or client.

An investor is buying a duplex. The listing shows strong rents. During due diligence, the investor finds that one lease is month-to-month at a lower rent than the rent roll showed. The sewer lateral inspection shows root intrusion, and the insurance quote is higher than expected.

The investor rebuilds the analysis with the real rents, a sewer repair estimate and the actual insurance quote. The numbers still work, but with less cash flow. They negotiate a credit for the sewer line and close with a clear plan and reserves.

Frequently Asked Questions

How I Can Help

As a broker and loan officer, I help investors plan due diligence from day one: scheduling inspections, reviewing leases and rent rolls, gathering expense records, rebuilding the analysis with real numbers and coordinating with lenders, title and escrow so deadlines aren't missed.

The Bottom Line

Due diligence is your chance to confirm a rental property before it's yours. Inspect thoroughly, review title, verify leases and rents, check permits, get insurance quotes early, rebuild expenses with real numbers, confirm financing and have an exit plan before removing contingencies.

Under contract on a rental? Let's build your due diligence plan together.

Sources

• Contractors State License Board, Hire a Contractor: https://www.cslb.ca.gov/Consumers/Hire_A_Contractor/
• California Civil Code §1950.5 (security deposits): https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=CIV&sectionNum=1950.5
• California Civil Code §1954 (landlord entry and notice): https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=CIV&sectionNum=1954
• California Attorney General, Limits on Rent Increases: https://oag.ca.gov/rentcaps
• California State Board of Equalization, California Property Tax: An Overview, Publication 29: https://www.boe.ca.gov/proptaxes/pdf/pub29.pdf
• California Department of Insurance, Residential insurance consumer guides: https://www.insurance.ca.gov/01-consumers/105-type/95-guides/03-res/
• FEMA Flood Map Service Center: https://msc.fema.gov/portal/home
• California Geological Survey, EQ Zapp: https://www.conservation.ca.gov/cgs/sh/eqzapp
• Consumer Financial Protection Bureau, Loan Estimate explainer: https://www.consumerfinance.gov/owning-a-home/loan-estimate/
• California Civil Code §4525 (documents provided to prospective purchasers): https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=CIV&sectionNum=4525

Get help with due diligence on a rental. Call or text me at 408-780-1188, or email onrealtygroup@gmail.com.

Oanh Nguyen · Broker & Loan Officer · On Realty Group, brokered by LPT Realty · BRE #02133991 · NMLS 2020335

Equal Housing Opportunity.

Loan disclosure: Oanh Nguyen, Broker | Loan Officer, On Realty Group, brokered by LPT Realty, BRE #02133991, NMLS #2020335. This post is general education, not a loan offer, rate quote or commitment to lend. Loan programs, guidelines and eligibility change and are subject to lender review and approval.

Disclaimer: This post is general information only, not an appraisal or legal, tax or financial advice; data comes from the public sources linked above, is believed reliable but not guaranteed, and can change at any time.