Pre-LOI Due Diligence Checklist: What to Review Before Signing an LOI

Quick answer

A pre-LOI due diligence checklist is the buyer's short-list of issues to test before signing a letter of intent. The goal is not full verification. The goal is to find the few financial, tax, legal, and process risks most likely to change conviction, price, or deal certainty before exclusivity begins.

Key takeaways

• Pre-LOI diligence should answer the few questions most likely to change conviction, not attempt full verification.
• The checklist should cover financial, tax, legal, and management/process risk before exclusivity starts.
• If a red flag would change price, structure, or willingness to proceed, it belongs in the pre-LOI scope.
• Bain argues that assured value capture starts with faster, deeper, and more focused diligence that considers integration implications during diligence rather than after it [Bain & Company, "Looking Ahead to 2025: Preparing for What Comes Next", 2025].
• A downloadable checklist is useful only if the team can tie tasks to evidence, owners, and escalation decisions once the live process begins.

Downloadable PDF

Unlock the pre-LOI diligence checklist PDF

Enter your email to get the pre-LOI checklist in PDF format for live deal screening.

The live site unlocks the PDF after email capture and records the conversion event.

Pre-LOI diligence exists to answer one question before the buyer enters exclusivity: is this deal worth the time, cost, and organizational attention that a full diligence process will require? That is why a good pre-LOI checklist is selective by design. If an item would not change conviction, price, structure, or willingness to proceed, it probably does not belong in the first-pass scope.

Buyers usually get this wrong in one of two ways. Some do too little and discover an obvious problem only after exclusivity starts. Others do too much and effectively run a post-LOI process before they have negotiated access, pricing guardrails, or a credible path forward. Bain's 2025 M&A report is directionally right on the remedy: the best acquirers use faster, deeper, and more focused diligence to prepare earlier for what comes next [Bain & Company, "Looking Ahead to 2025: Preparing for What Comes Next", 2025].

What pre-LOI diligence should decide

The pre-LOI phase is not meant to prove everything. It is meant to decide whether the core economics and transferability of the deal are strong enough to justify exclusivity.

In practical terms, the checklist should help the buyer answer five questions:

1. 1. Is the earnings story believable enough to keep going?
2. 2. Is there any obvious tax, legal, or regulatory issue that could change value quickly?
3. 3. Are the most important contracts, customers, or management assumptions fragile?
4. 4. Does the seller appear organized and transparent enough for a serious process?
5. 5. Would a negative answer on any of the above change the LOI or stop the deal altogether?

That framing matters because pre-LOI diligence is about decision quality, not checklist completeness.

How to use this checklist

Use the checklist as a priority filter, not a compliance file. The objective is to identify the small set of issues that would make you:

• lower price
• change structure
• require specific conditions before exclusivity
• tighten the access plan or early workstream scope
• move faster because the core risk looks manageable
• pause or walk entirely

Bayes Business School reported that the average pre-announcement due diligence period reached 203 days across studied deals from 2013 to 2022 [Bayes Business School, "Cautious M&A investors taking extra care with due diligence", 2024]. That is a useful reminder that even long processes create pressure to focus. If the buyer cannot identify the conviction-changing questions early, the process becomes longer without becoming sharper.

Financial review before LOI

Before signing an LOI, buyers should test whether the headline earnings story is directionally believable.

• Review revenue concentration and ask whether one customer, product line, or channel is carrying the thesis.
• Pressure-test the bridge from reported EBITDA to management's adjusted EBITDA.
• Check whether margin changes are explainable by mix, pricing, volume, or one-time items.
• Look for obvious working capital stress, cash conversion weakness, or unusual balance-sheet movements.
• Ask whether the current forecast depends on assumptions management cannot yet support.

The standard is not full proof. The standard is whether the financial story is strong enough to justify moving into exclusivity without discovering an avoidable surprise in week two of full diligence.

The buyer should also decide which financial questions are too important to defer:

• Is reported growth supported by durable demand or just timing?
• Are margins improving because the business is stronger, or because costs are temporarily suppressed?
• Are management adjustments modest and explainable, or aggressive and still moving?
• Does the balance sheet support the earnings story, or contradict it?

If the first document set cannot support a credible view on those questions, the buyer should not pretend the risk is low simply because the process is early.

Commercial and market checks before LOI

Many buyers treat pre-LOI diligence as purely financial. That is a mistake, especially when the valuation assumes continued growth or a premium multiple.

The commercial layer should test whether the market narrative is strong enough to survive deeper review:

• Is customer demand broad-based or concentrated in a few relationships?
• Are the recent growth drivers repeatable, or were they driven by unusual events?
• Does pricing appear durable, or is margin expansion likely to reverse under competitive pressure?
• Are churn, renewal, or backlog metrics consistent with management's narrative?
• Does the business depend on distributors, partners, or channels that could become unstable after a change of control?

This is still not the full commercial diligence workstream. It is the early screen that tells the buyer whether the valuation case deserves deeper underwriting.

Tax and structure checks before LOI

Tax diligence before LOI should focus on exposures that can change value quickly and structure decisions that are hard to unwind later.

• Confirm whether the company operates in more states or countries than management's tax footprint suggests.
• Identify whether NOLs or credits are part of the valuation story and whether Section 382 or similar limitations may reduce their usefulness.
• Ask whether remote employees, distributed operations, or recent expansion may have created unrecorded SALT exposure.
• Look for obvious deferred-tax or reserve issues that suggest timing differences or uncertain positions were not fully understood.
• Flag any transaction-structure questions that could materially change the buyer's economics.

The goal is not a full tax memo. The goal is to decide whether tax risk is minor, manageable, or serious enough to change the initial offer posture.

Legal and contract review before LOI

Legal diligence before LOI should focus on transferability and concentration of contract risk.

• Pull the highest-value customer and supplier contracts first.
• Test for change-of-control and assignment language in agreements that matter most to the revenue base.
• Ask whether key licenses, IP rights, or distribution rights transfer cleanly after an acquisition.
• Check whether unusual indemnities, exclusivity provisions, or regulatory obligations could distort deal economics.
• Confirm whether there is pending or threatened litigation that would change the risk picture before exclusivity.

If the target has a concentrated contract base, this section can matter more than a long general legal checklist. One or two consent-driven contracts can change the buyer's entire confidence score.

Management and process checks

Pre-LOI diligence should also test whether the process itself is likely to hold together.

• Is management responsive, organized, and internally consistent?
• Are the first diligence materials complete enough to support a serious initial view?
• Does the team have a coherent explanation for major growth, margin, or working-capital shifts?
• Are they transparent about open issues, or do basic answers require repeated chasing?
• Is there an obvious integration, reporting, or governance problem that would become painful immediately after close?

Boston Consulting Group reported that large deals averaged 191 days from announcement to close in 2024 and that about 40 percent of transactions took longer to close than expected [Boston Consulting Group, "The 2024 M&A Report: Deals Are Taking Longer to Close. How to Respond.", 2024]. Delays do not all begin in pre-LOI work, but weak early screening often guarantees that avoidable surprises resurface later under more pressure.

What to request in the first document pack

The best pre-LOI reviews do not start with a generic data-room dump. They start with a deliberate first request list that supports a fast conviction test.

A useful first pack usually includes:

• trailing monthly financial statements and a current-year budget or forecast
• a bridge from reported EBITDA to management's adjusted EBITDA
• customer concentration or top-customer data
• the highest-value customer, supplier, and partner contracts
• a high-level tax footprint by jurisdiction
• organization chart, key management biographies, and basic reporting materials
• any recent board deck, lender presentation, or strategic planning summary the seller is willing to provide

That request list is intentionally narrow. The point is to get enough signal to decide whether the buyer should go deeper, not to recreate post-LOI diligence prematurely.

When the checklist should change the LOI

Pre-LOI work has only done its job if it changes the buyer's posture when needed.

The checklist should influence the LOI when it surfaces:

• a material earnings-quality concern that changes the valuation base
• contract-transfer or customer-concentration risk that threatens deal certainty
• tax or legal exposure that warrants a specific diligence condition or pricing adjustment
• evidence that the seller's process is too fragmented to support clean exclusivity
• a management credibility issue serious enough to weaken the underwriting case

The output should not just be a note saying "more work required." It should be a sharper point of view about price, structure, scope, and access.

How AI fits before LOI

AI can help the pre-LOI phase because it makes early triage faster and more systematic. Deloitte reported that 86 percent of surveyed organizations have integrated GenAI into their M&A workflows [Deloitte, "2025 GenAI in M&A Study", 2025]. That is relevant at the screening stage because buyers increasingly need to review more material, earlier, with less tolerance for manual waste.

But AI only helps if the team preserves the judgment layer. Faster parsing does not fix poor source materials, weak management answers, or a badly scoped request list. It simply gets the buyer to those problems faster.

How Sorai helps

The checklist is useful only if the work does not disappear after the first pass. Sorai turns pre-LOI screening into a live workflow where issues, evidence, and reviewer commentary can move directly into post-LOI execution if the deal advances.

That matters because the best pre-LOI process is not just fast. It is reusable. If the deal moves forward, the buyer should not have to rebuild the story from scratch. The initial red flags, open questions, and support trail should already be positioned to carry into the deeper diligence stage.

The bottom line

Pre-LOI diligence is not a miniature version of full diligence. It is the buyer's first serious decision filter. A strong pre-LOI checklist identifies the few issues most likely to change conviction, price, structure, or willingness to proceed, and it does that early enough to matter.

That is the standard. Not volume. Not motion. Not a thick file of early notes. A better first answer before exclusivity starts.

Sources cited

1. Bain & Company, "Looking Ahead to 2025: Preparing for What Comes Next", 2025
2. Deloitte, "2025 GenAI in M&A Study", 2025
3. Boston Consulting Group, "The 2024 M&A Report: Deals Are Taking Longer to Close. How to Respond.", 2024
4. Bayes Business School, "Cautious M&A investors taking extra care with due diligence", 2024

Author

Sorai Editorial

Editorial review team for Sorai's public diligence content

The editorial team translates public primary-source research and Sorai's workflow perspective into material designed for private equity, corporate development, and transaction advisory readers.

What is pre-LOI due diligence?

It is the focused review buyers perform before signing an LOI to decide whether the deal deserves exclusivity and deeper diligence investment.

How deep should pre-LOI diligence go?

It should go deep enough to test the few issues most likely to change conviction, price, or structure, but not so deep that the team runs a full post-LOI process before exclusivity.

What belongs on a pre-LOI diligence checklist?

The checklist should cover core financial quality, tax exposure, contract transferability, management quality, and the practical process risks that could derail the deal early.

Should buyers use AI before LOI?

Yes, but only inside a disciplined process. Deloitte reported that 86% of surveyed organizations have integrated GenAI into their M&A workflows, which makes early triage faster when humans stay responsible for escalation and final judgment [Deloitte, "2025 GenAI in M&A Study", 2025].

Go deeper

Move from process theory into the workstreams.

Use the service pages below to review how Sorai supports pre-LOI screening, full diligence, and review-readiness across the deal cycle.

Pre-LOI

Pre-LOI Due Diligence: The Buyer's Confidence Assessment

Pre-LOI due diligence helps buyers test the deal thesis, identify the highest-risk issues early, and decide whether to proceed, pause, or narrow the scope before exclusivity begins.

Deal Timing

Why M&A Due Diligence Takes So Long (And How to Fix It)

M&A diligence slows down because workflows fragment, file readiness stays weak, and the final decision narrative gets rebuilt too late. Here is how disciplined teams shorten the timeline.

Quality of Earnings

Quality of Earnings: A Complete Guide for M&A Buyers

A buyer-focused guide to quality of earnings analysis in M&A, including what QoE actually tests, which findings change price and terms, and how to run the work under deal pressure.