Due diligence: what to verify before you buy any small business

Due diligence has a reputation as paperwork — a box-checking phase between the handshake and the closing. That reputation gets people hurt. Diligence is the part of buying a business where you find out whether the story you were sold is true, and it's the only part of the process where walking away is cheap. After closing, every problem you didn't find becomes a problem you own.

Here is the whole discipline in one sentence: assume nothing you were told is true until you've seen the evidence, and treat anything that can't be evidenced as if it doesn't exist. Everything below is that sentence applied to the four places sellers' stories and reality diverge.

1. The money: verify, don't audit-by-vibes

Start with documents the seller didn't prepare for the sale:

• Tax returns, several years — the version of the story told to the government, which is the version told against the seller's interest. Your CPA should see these; a seller who resists sharing returns (with sensitive details redacted early on if they insist) is answering a question you didn't ask yet.
• Bank and card-processor statements — deposits are harder to embellish than spreadsheets. Match claimed revenue to actual money movement.
• Third-party records the business sheds naturally — utility bills, booking-system reports, management-software rent rolls, supplier statements, payroll records. Every business type leaks its own kind of evidence; the vertical guides on this blog (laundromats — with the P&L rebuild walked in full in are laundromats profitable? — campgrounds, storage, HVAC) are largely maps of where.

Then interrogate the differences. The gap between the P&L and the returns, between claimed and deposited, between the trend the seller describes and the trend the third-party records show — those gaps are the actual findings of diligence. Some have innocent explanations. Get the explanation, then verify that.

And the standing rule, which no seller charm repeals: income you cannot verify is worth nothing in your price. "There's cash that doesn't show up in the books" is not upside. It's either untrue or an admission — and you can't finance, resell, or rely on either one.

2. The obligations: what comes attached to what you're buying

The business's earnings arrive attached to commitments, and diligence means reading every one:

• The lease — for many businesses on this blog, the lease is the business. Remaining term, renewal options, escalations, transfer/assignment terms, and what the landlord must consent to. An attorney reads this; you don't sign against a summary.
• Contracts you'd inherit — customer agreements and their promises, supplier commitments, equipment leases, service contracts, franchise or license agreements. Which ones transfer, which need consent, which die with the sale?
• Employees — who's owed what (wages, accrued time off), who's critical, and what happens to them at close. In services businesses this is the whole deal; see the HVAC guide for how deep that goes.
• Debts and liens — confirm through your attorney what claims exist against the business's assets and how the purchase is structured so you don't inherit surprises. Deal structure — what you're buying, what stays with the seller — is precisely the thing the attorney and CPA are for, and it changes what diligence must cover.

3. The permissions: can you legally run this business tomorrow?

Licenses, permits, zoning, health department approvals, professional qualifications — every business operates inside a set of permissions, they vary by industry and by state and locality, and they do not all transfer with a sale. For each one: does it exist, is it current, is it in the business's name or the seller's, and what does your path to holding it look like? Verify with the issuing authority, not the seller's recollection. (Food trucks are this problem at its most concentrated — a food truck business plan a lender will actually read shows what verified-with-the-issuing-authority looks like in practice.) A business you can't legally operate on day one isn't a business yet, whatever you paid.

4. The story: why is this being sold, really?

Every seller has a reason, most stated reasons are partially true, and the missing part is usually where your risk lives. New competitor, a lease reset coming, key employee leaving, equipment at end of life, a road project, a market shifting under the model. You won't get this from the data room — you get it by triangulating: the records above, time spent at the business, conversations with the landlord and (carefully, late in the process) suppliers and staff, county records, local news. Diligence isn't only reading documents. It's noticing what the documents are quiet about. That habit doesn't retire at closing, either — the same reading applies to every report, invoice and vendor pitch that reaches you once you own the place.

Run it in the right order

Sequence saves months: money first (if earnings don't verify, nothing else matters), deal structure and obligations second with attorney and CPA engaged, permissions and story throughout, and price at the end — because your offer should be the output of what you verified, via the valuation discipline, and your financing file is assembled from the same documents (what lenders look at). One process, gathered once.

And the ending nobody selling you anything likes to write: a good diligence process regularly concludes "don't buy this." That's not failure — that outcome, delivered before closing instead of after, is the entire return on the work. The buyers who do well are the ones who walked away from the deals that deserved it and were still standing when the right one listed.