You've found a business you like, agreed on a price in principle, and signed a letter of intent. Now comes the part that actually protects you: due diligence. A thorough due diligence checklist is what separates buyers who find out about problems before closing from buyers who find out after — when it's their problem to fix. Here's what to verify before you sign anything final or wire a deposit.
Due diligence isn't about catching the seller in a lie — most sellers are straightforward, and most businesses check out close to how they were represented. It's about confirming that on your own, with documentation, rather than taking the listing description on faith. Buyers who skip this step because a deal "feels right" are the ones most likely to discover an unpleasant surprise a few months after closing, once it's their name on the lease and their money on the line.
What Financial Records Should You Review?
- Three to five years of tax returns — compare them against the financials the seller presented. Discrepancies are a red flag worth investigating, not ignoring.
- Profit and loss statements and balance sheets — ideally reviewed or compiled by an accountant, not just a spreadsheet the owner maintains.
- Bank statements — to confirm deposits roughly match reported revenue.
- Accounts receivable and payable aging — old, uncollected receivables or a stack of unpaid bills tell you something about how the business is really being run.
- Add-backs in the SDE calculation — every "personal expense run through the business" the seller claims should be backed up with documentation, not taken on faith.
What Legal and Contractual Documents Do You Need?
- The lease — confirm it's transferable or that the landlord will sign a new lease with you, and check the remaining term against your plans.
- Customer and vendor contracts — especially any contract responsible for a large share of revenue, and whether it requires consent to assign upon a change of ownership.
- Licenses and permits — confirm which ones transfer with the business and which you'll need to reapply for in your own name.
- Pending or past litigation — ask directly, and verify with a court records search rather than relying solely on the seller's disclosure.
- Employee agreements and any non-competes — understand what obligations transfer and what you're taking on with the team.
- Insurance policies — general liability, workers' comp, and any industry-specific coverage, along with the claims history behind them.
- Corporate documents — articles of incorporation, bylaws or an operating agreement, and confirmation the entity is in good standing with the state.
What Operational Details Are Easy to Miss?
Financials tell you what the business earned. They don't tell you how dependent it is on the current owner, how satisfied customers actually are, or whether key employees plan to stay after the sale. Spend time on-site, talk to a sample of customers if the seller allows it, and ask the seller directly what would break if they left tomorrow. If the honest answer is "everything," price and plan accordingly — you're buying a job, not a business, until you build systems to change that.
Also walk the physical operation, not just the numbers. Check the condition of equipment against what's on the fixed asset list, confirm inventory counts match what's reported, and ask about any software or systems the business depends on, including whether logins and accounts are tied to the owner personally rather than the business. Systems that live in one person's head or personal accounts are a common source of post-closing headaches.
What Questions Should You Ask the Seller Directly?
Documents tell you what happened. Direct conversation with the seller often tells you why — and what's likely to happen next. Beyond the paperwork, ask: Why are you selling, specifically? What would you change about the business if you were staying? Which customers or employees are most at risk of leaving after a sale? Has revenue or margin changed meaningfully in the last two years, and why? A seller's answers, and how directly they answer, often reveal more than another spreadsheet will.
How Long Should Due Diligence Take?
For most small business acquisitions, plan on 30 to 60 days between signing a letter of intent and closing. Rushing this stage to "not lose the deal" is how buyers end up owning problems they could have caught. A seller who resists reasonable requests for documentation, or gets defensive about routine questions, is telling you something important before you've spent a dollar.
It's normal for the timeline to extend if something you find needs a closer look — an unexpected lease issue, a customer contract that needs the other party's sign-off, or financials that need another round of clarification. A good letter of intent builds in a reasonable diligence period with the option to extend, rather than a hard deadline that pressures you to skip a step just to stay on schedule.
Working through due diligence with an experienced broker on your side catches issues a first-time buyer might miss entirely. If you're evaluating a specific business right now, get in touch with Silver Surf and we'll help you think through what to verify before you commit. For the full picture of what comes before and after this stage, see our step-by-step guide to buying a business.
FAQ
1. How long does due diligence take when buying a business?
Most small business acquisitions take 30 to 60 days for due diligence, between signing a letter of intent and closing.
2. What financial documents should I ask for during due diligence?
Three to five years of tax returns, profit and loss statements, bank statements, and a documented SDE calculation with support for every add-back.
3. What's the biggest red flag during due diligence?
A seller who resists reasonable requests for documentation or gets defensive about routine questions — that reaction often tells you as much as the numbers do.
4. Who should be involved in due diligence besides the buyer?
An accountant to review financials and an attorney to review contracts, leases, and legal exposure — due diligence isn't something to handle entirely alone.