What Buyers Are Actually Looking at in Due Diligence in 2026

Diligence has always been thorough. What has changed in 2026 is where buyers are spending the most time and what is tripping up sellers who thought their business was ready to sell. If you are planning a transaction in the next one to three years, understanding the current diligence focus is one of the most practical things you can do to protect your outcome.

The shift is not toward more diligence. It is toward more targeted diligence in specific areas. Buyers have gotten better at identifying the issues that matter most to value, and they are going deeper on those issues than they did three or four years ago.

Durability of Earnings

This is the single biggest focus area right now, and it goes well beyond reviewing your P&L. Buyers want to understand whether your revenue is genuinely recurring or whether it renews every year because your sales team and customer relationships happen to hold it together. They want to understand whether your margins are structurally stable or whether they have benefited from temporary cost conditions that will not persist.

They will reconstruct your EBITDA from scratch using their own normalization assumptions, not yours. That reconstruction includes removing owner benefits, one-time revenue events, and cost items that would not recur under new ownership. The gap between your adjusted EBITDA and the buyer’s adjusted EBITDA is where the first major negotiation happens. Sellers who have done this work themselves before going to market enter that conversation from a much stronger position.

Customer Concentration

If your top two or three customers represent more than 30% to 40% of your revenue, every sophisticated buyer will flag this as a risk. The concern is not that those customers might leave tomorrow. The concern is that the value of your business is contingent on relationships the buyer cannot control and may not be able to maintain after ownership changes.

Buyers will look at the contract structure for your top customers. Month-to-month relationships are treated differently than multi-year contracts. They will also look at the trend: is customer concentration improving over time as you add smaller accounts, or is it worsening as one or two accounts grow faster than the rest? And they will ask how long you have held those relationships and how many of them are personal to you rather than institutional to the company.

This is fixable before a process starts. It requires deliberately building and retaining a broader customer base over 12 to 24 months. It is much harder to fix once you are in a diligence process and a buyer has already quantified the concentration risk.

Owner Dependence

Calder Capital’s 2026 analysis calls owner involvement one of the top scrutiny areas in current lower middle market diligence. The question buyers are asking is: what happens to this business if the owner is not there six months after the sale?

For many business owners, the honest answer is uncomfortable. The key customer relationships run through you. The operational decisions run through you. The team morale runs through you. Buyers see that dependence as risk, and they discount for it. The discount is not a small one: a business that needs the owner to function is worth meaningfully less than an identically sized business that runs on documented systems and capable management.

Reducing owner dependence takes time. It requires delegating decision-making authority in ways that feel uncomfortable, building and retaining a management layer below you, and documenting processes that currently live in your head. None of this can be credibly demonstrated in a 90-day process. Buyers can tell the difference between genuine operational independence and a cleanup job started two months before the LOI.

Management Depth

Related to owner dependence but distinct from it: who is running the business below the owner level, and what happens to them in a sale? Buyers, particularly PE buyers, want to see a management team they can retain and build on. A business where the second tier of leadership is strong and engaged is dramatically easier to acquire than one where the owner is the only real leader and the team beneath them is junior.

If your key people do not have equity stakes or retention incentives tied to a sale, think carefully about that before you go to market. Buyers will ask. They may make retention packages a condition of closing. And the time to build the management team you will present to buyers is not during the process.

Financial Reporting Quality

Inconsistent financial reporting is the most common deal-staller in lower middle market transactions right now. This includes businesses that have used multiple accounting methods across years, that have intermingled personal and business expenses, that have not maintained clean records of related-party transactions, or whose revenue recognition practices do not hold up to scrutiny.

You do not necessarily need audited financials to run a successful sale process, though they help. You do need three years of financials that are consistent, explainable, and prepared on the same basis. If your books have issues, addressing them before a process starts is always better than discovering them alongside the buyer’s diligence team.

For a broader look at how to address these issues before going to market, see How to Use AI to Prepare Your Business for Sale and the full Icon Exit process.