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How Long Does Due Diligence Take?

How Long Does Due Diligence Take?

POSTED November 8, 2026
BY Matt Aubin

Matt is both the company founder and a nationally renowned private investigator. Matt is an intelligence specialist who excels in detecting and preventing the illegal interception of communications and in providing high-tech covert surveillance. Matt has years of hands on experience in the investigation industry and has developed a reputation for incorporating state of the art technology and innovative ideas to provide effective solutions for his clients. Matt also serves as Treasurer for the Executive Board of Directors of FALI, The Florida Association of Licensed Investigators.

Due diligence on a business purchase is scheduled for 60 days after a signed letter of intent, and slow seller documents push it past that. The 60-day figure covers the financial and legal review. At Southern Recon Agency, our investigators work a separate piece of that window, confirming who the people across the table are and what they left out.

Key takeaways

  • M&A due diligence is planned for 60 days after a signed letter of intent, and experienced dealmakers prepare for 90.
  • In a Q4 2023 survey of 150 investment bankers, 44% said a typical deal takes 5 to 6 months from first information sharing to closing.
  • Florida’s As Is residential contract sets a 15-day inspection period when the parties leave that blank empty.
  • A due diligence investigation of the people behind a deal takes days to weeks or longer, with the timeline set at scoping.

How long due diligence takes by type

Due diligence takes anywhere from 15 days to 6 months, and the answer turns on which type a deal or contract calls for. The phrase covers several separate reviews, each running on its own clock. A buyer who plans around a single number often finds out late that one review never got scheduled.

Type of due diligenceHow long it takesWho runs it
Business acquisition, financial and legal review60 days planned after the letter of intentBuyer's accountants and attorneys
Whole deal, first information sharing to closing5 to 6 months, per 44% of bankers surveyed in Q4 2023Deal team
Florida home purchase on the As Is contract15 days by defaultBuyer and home inspectors
Due diligence investigation of people and entitiesDays to weeks or longer, set at scopingLicensed investigators
Database background checkMinutesOnline record service

Business purchases draw most of the searches. Bill Snow, author of Mergers & Acquisitions For Dummies, tells buyers and sellers alike to push for a 60-day due diligence period. Sellers who send records slowly are the usual reason a deal runs past it.

The whole deal lasts far longer than the diligence window. SRS Acquiom and Mergermarket surveyed 150 senior investment bank executives in Q4 2023, and 44% said a typical M&A deal takes 5 to 6 months from first information sharing to closing.

Several workstreams share that window: financial, legal, operational, and the check on the people, which we handle through our corporate investigations in Florida.

How long does due diligence take once a letter of intent is signed?

Plan for 60 days and brace for 90. Bill Snow’s benchmark holds that M&A due diligence should take no longer than 60 days after both sides sign the letter of intent. He also advises preparing for 90 days, since sellers and advisers rarely move as fast as a buyer wants.

How long is the due diligence period on a Florida home purchase?

Florida’s As Is residential contract, the form used more than any other for home sales in the state, measures the inspection period in days after the effective date and defaults to 15 days when the blank is left empty. Buyer and seller can write in a different number. Contracts in other states follow their own forms and deadlines.

What delays due diligence

Due diligence gets delayed when the seller sends documents slowly and when the buyer cannot trust what arrives.

Bankers in the Q4 2023 survey were asked about their latest buy-side deal. Vetting the information they received ranked as the top challenge, with 31% of top-two votes, and unreliable or unclear data followed at 25%.

Timelines keep stretching. When SRS Acquiom and Mergermarket repeated the survey in Q4 2025, one in five respondents said due diligence timelines had grown over the past two years, and 57% of that group said the process had gained one to three months.

In the same 2025 survey, 47% of respondents named technology due diligence as their main priority over the past 12 months. Checking the people behind the deal is a separate job, and it has to be scheduled on purpose.

Can due diligence be shortened without compromising quality?

Yes, by starting every review on day one and running them side by side. Sellers who assemble their records ahead of the letter of intent remove a common delay. Buyers save the most time by ordering the investigation of the principals at the start, since findings that arrive in the final week leave little room to act.

Where a due diligence investigation fits in the timeline

A due diligence investigation fits at the front of the timeline, starting the week the letter of intent is signed.

Accountants review the books and attorneys review the contracts, and neither is hired to find out if the seller left a string of failed companies under an earlier name.

Our investigators take that question. A due diligence investigation looks at the people and entities behind a deal: their work history, their court records, their licenses, and the businesses they owned and closed.

Scheduling works backward from the closing date. E3 Legacy Intel, the firm’s intelligence division, builds each scope around that date so findings land while they can still change the decision.

Example (illustrative only): Two buyers in Orlando each sign a letter of intent with a 60-day exclusivity window. The first orders an investigation of the seller in week one. Midway through the window she learns the seller holds an undisclosed stake in the company’s largest supplier, and she renegotiates the price with weeks to spare. The second buyer orders the same work in week seven. His report arrives two days ahead of closing, leaving him to sign blind or ask for an extension the seller has little reason to grant.

Ordering the investigation in week seven is like checking a roofer’s license once the old roof is already off. The answer still arrives, and the choice it was meant to inform has been made.

How long does a due diligence investigation take?

A due diligence investigation takes days in simple matters and weeks or longer in complex ones, and the timeline is set at scoping. Three things drive it: the number of people, the companies tied to them, and the states or countries where records sit. A fixed closing date shapes the scope, so share it on the first call.

Is a background check the same as due diligence?

A background check is one piece of due diligence. Database background checks return records filed under the exact name searched, often within minutes. A due diligence investigation goes further by verifying claims against source records and tracing company ownership to the people in control. Our background checks in Florida range from basic to in-depth.

Have a closing date and a counterparty you have not verified?

Our investigators check the people and companies behind a deal and report what the paperwork leaves out.

See what a due diligence investigation covers

Confidential, and handled by a licensed Florida investigator.

What a due diligence investigation checks

A due diligence investigation checks the personal and business history of each party against the record, and our baseline scope covers seven areas:

  • Professional and personal work history, including omissions and misstatements on a resume
  • Professional and personal social media
  • Criminal court case history
  • Civil court history, including judgments, liens, foreclosures, and bankruptcies
  • Regulatory records and professional licenses
  • Undisclosed corporate ownership interests
  • Failed businesses and dissolved companies

Each area lives in a different set of records, which is why the work takes investigator hours instead of a single search. Court files sit with individual courts and company filings sit with each state, so a seller who has operated in three states leaves three trails.

Hiring decisions follow the same logic on a smaller scale, and our background screening for businesses applies it to executives and key hires.

Red flags:

  • A lawsuit, judgment, or lien filed under a prior company name
  • A business that closed and dropped out of the seller’s biography
  • An owner of record who cannot be tied to a real person in control
  • A license, credential, or past sale that no outside record confirms

Red flags like these call for a wider scope and, where the contract allows, more time.

When to start due diligence on a business purchase

Start due diligence on a business purchase the day the letter of intent is signed, and start the investigation of the seller in the same week.

Buyers on a budget often sequence the work to control cost: financials first, attorneys second, everything else if time remains. A problem in the seller’s history costs the most when it surfaces last, after the buyer has paid for every other review.

Recommended:

  • Order the investigation the week the letter of intent is signed.
  • Give the investigator the closing date on the first call.
  • List every company name, prior name, and state of operation for each principal.
  • Ask for the timeline in writing with the quote.
  • Tell your attorney the investigation is under way so the findings can shape the purchase agreement.

Attorneys running a deal often order the work on a client’s behalf, and our investigation services for attorneys are set up for that arrangement.

TL;DR

Due diligence on a business purchase is planned for 60 days after a signed letter of intent, and many bankers put a whole deal at 5 to 6 months from first information sharing to closing. Florida’s As Is home contract defaults to a 15-day inspection period. Slow seller documents and unverified information are the delays deal advisers point to. The investigation of the people behind a deal has its own timeline, set at scoping, and it belongs in week one.

About to sign with someone you know only from a pitch deck?

Find out who they are while the answer can still change your decision. Southern Recon Agency investigates the people and companies behind a deal and documents the findings for you and your attorney.

Request a confidential case review

Call (844) 307-7771. Florida licensed agency A1400197.

Frequently asked questions

How long does due diligence take when buying a business?

Plan on 60 days after the letter of intent for the financial and legal review, and longer if the seller is slow with records. From the first exchange of information to closing, 44% of the 150 investment bankers surveyed by SRS Acquiom and Mergermarket in Q4 2023 put a typical deal at 5 to 6 months.

Can a due diligence investigation be rushed if closing is near?

A closing date that is close calls for a narrower scope. The firm’s intelligence division offers a focused red-flag review for that situation, which prioritizes the findings most likely to affect the deal. The trade is depth, so a rushed review covers fewer people, companies, and jurisdictions than a full investigation would.

Will the other party know they are being investigated?

Due diligence investigations are conducted discreetly and through lawful means by licensed investigators, and findings go privately to the client who ordered the work. Where a matter touches an employment decision, compliance requirements are addressed at scoping so the findings stay usable. Raise any concern about discretion on the first call.

How much does a due diligence investigation cost?

Cost is quoted after an assessment of the matter. The firm quotes each due diligence engagement as a flat fee in writing, and the number of people, companies, and jurisdictions involved drives the figure. Ask for the quote and the timeline together, since both come out of the same scoping conversation.

Does due diligence continue after closing?

Due diligence can continue after closing as monitoring. The firm’s intelligence division offers post-close monitoring that watches a counterparty for new litigation, financial distress, and reputational events. Monitoring suits lenders, funds, and companies whose relationship with the other party lasts beyond the closing date.

About the author

Matt Aubin is the Founder and Managing Partner of Southern Recon Agency, a Florida-licensed private investigation agency (License A1400197) based in Orlando, which he started in 2010. He is a Certified TSCM Technician, a Certified Digital Forensics Examiner, and a Florida Board Certified Investigator, and a court-qualified expert witness in cyber intelligence and cyber forensics. Mark J. Aubin, J.D., a practicing attorney and the firm’s in-house legal counsel, heads corporate investigations.

Everything in this article is general information and is not legal or financial advice. Contract terms and deadlines differ by state and by deal. For guidance on a specific transaction, consult a licensed attorney in your state.

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