Buying a business is not a leap of faith, it is a checklist you can run in days. The point of due diligence is simple: prove the earnings, surface the risks, and decide the exact price and structure that will survive month one. For a broader framework to cross-reference while you work a live deal, read Mergers & Acquisitions (M&A): The Complete SME Buy & Exit Playbook.
In this article, we’re going to discuss how to:
- Build a fast, founder-friendly due diligence plan you can run in 10 days
- Verify the money trail across finance, legal, tax, operations, and customers
- Turn findings into pricing, pegs, and protections that keep day-two cash safe
Due Diligence, Defined In Practical Terms
Due diligence is the short, disciplined process of turning a seller’s story into operator truth. You are not hunting for perfection, you are deciding whether the business can service debt, pay salaries, and keep customers when you own it.
Quick sense checks:
- Cash beats theory: favour 12 to 36 months of consistent monthlies over projections.
- One person risk kills value: if the owner is the top salesperson, price or structure for it.
- Base case must work: debt service should clear 1.5x after a realistic working capital peg.
The 10-Day Diligence Sprint
Move with a timetable. Ten clean days beats ten messy weeks. Appoint owners for finance, legal, tax, operations, and commercial. Publish a request list on day one, hold two short chase-downs per week, and send a Friday status note that lists what moved and what did not. Speed is a decision, and it signals seriousness to sellers and lenders.
Day one to three is for financial truth and document sanity. Day four to seven is for customer calls, supplier checks, and walking an order from quote to cash. Day eight to ten is for systems, data, and the working-capital peg. If a single point of failure can wipe out a year of profit, either price it in or walk.
Financial Diligence: Prove The Earnings
Start with the bank, not the deck. Tie revenue to invoices and cash received. Rebuild gross margin by product or service line directly from source documents. Normalise EBITDA by adding genuine one-offs and owner perks, then subtracting underpaid wages you must pay a replacement. Restate rent at market if needed and strip out non-business costs. If you cannot reconcile last month’s closing cash across the statements and ledgers, stop until you can.
Pay close attention to seasonality and revenue recognition. For project-heavy firms, match costs to the period they earn the revenue, not when they were paid. For recurring revenue, test churn in heads, not just percentages, and make sure discounts and credits are included in the numbers you are reading.
Legal Diligence: Contracts, Title, And Claims
Legal work is not theatre. Focus on what changes ownership risk. Review constitutional documents, share registers, options, and charges. Pull the top 20 customer and supplier contracts and flag assignment or change-of-control clauses. Read leases for term, breaks, dilapidations, and rent review mechanics. Confirm IP ownership with assignments from contractors and check for trademark conflicts. Ask for a litigation and disputes schedule and match entries to any provisions in the accounts.
Decide early whether completion accounts or a locked box fits the trading pattern. If you choose a locked box, define leakage precisely and appoint an expert accountant as dispute referee. If trading is volatile, completion accounts usually protect both sides.
Tax And Compliance: No Surprises With HMRC Or FTA
Map every tax that touches the business: corporation tax, VAT, payroll, and any sector-specific items. Reconcile VAT returns to the trial balance and bank. Match payroll filings to ledger and contracts. Ask for any HMRC or FTA correspondence and check payment plans or time-to-pay arrangements. In regulated sectors, confirm licences are current and transferable. If the company trades in the UAE, understand how the federal corporate tax applies and whether any free zone provisions matter to your revenue mix.
Operational Diligence: How Work Really Gets Done
Follow a live job from quote to cash. Time hand-offs. Look for rework, delays, and duplicated data entry. Map the real org chart, not the pretty one. Who opens and closes each day, who can approve discounts, who orders stock, and who chases cash. If the same name appears on every answer, you have a key person problem.
Observe first-time fix in service businesses and right-first-time in production. Small percentages compound into cash. A two-point improvement in first-time fix can remove a week of wasted labour a month. The best integrations start with simple changes that cut failure demand before you touch the tech stack.
Customer And Revenue Quality: Retention Beats Hype
Ten short customer calls beat a hundred pages of research. Ask what they buy, why they stay, what would make them leave, and who else they considered. Confirm renewal dates and the real price paid, not just list. Pull churn data in heads, not percentages. If one client is over 25 percent of revenue, treat that as a pricing lever or tie part of the earn-out to renewal of named accounts.
For product firms, examine cohort behaviour and repeat purchase rates. For subscription or service firms, inspect net revenue retention and gross churn. Price rises are only credible if delivery is stable and you have evidence customers accept them.
Working Capital And Stock: Set The Peg Properly
Your working-capital peg protects day-two cash. Calculate the trailing 12-month average for receivables, payables, and stock. List the exact accounts that qualify. Pull a stock ageing report and carve out slow-moving or obsolete lines at below cost. If the business is seasonal, set the peg with seasonality in mind rather than a flattering single month. The peg deserves more attention than haggling for a tiny point on headline price because it protects the same pound with higher certainty.
Cyber, Data, And Systems: Quietly Critical
Export user lists and admin rights for core systems. Check whether multi-factor authentication is enforced and whether backups are tested. Review the CRM, billing, and helpdesk data for duplicates and missing fields. Confirm that you can extract clean lists for invoicing and collections on day one. You do not need a big platform migration in month one, you need quiet reliability and clear ownership of each system.
Red Flags, Hedges, And Repricing Moves
When you find risk, do not ignore it or dramatise it. Hedge it.
- Price concentration risk: Reduce the multiple by 0.5 to 1.0 turn or link part of the earn-out to renewal of named accounts.
- Documentation gaps: Lower cash at completion and move value into vendor notes or holdback. Add a short, capped earn-out with monthly reporting.
- Key person dependency: Retention bonuses tied to specific deliverables and a 60-day shadow plan with documented hand-offs.
Due Diligence Documents: The Short List To Request
Keep the first ask tight so momentum stays with you.
- Financial pack: Monthly P&L, balance sheet, and bank statements for 24 months.
- Working capital: Aged receivables and payables, stock ageing, and draft peg.
- Contracts and legal: Top 20 customer and supplier contracts, leases, IP assignments, charges, litigation schedule.
- People: Staff list with role, tenure, salary, notice, and disputes.
- Systems: CRM, billing, and helpdesk exports, admin access list, and backup policy.
Micro Cases: What Good Looks Like
Managed IT, North West: £1.9m revenue, £360k normalised EBITDA, 140 customers, no single client over 17 percent. Diligence rebuilt gross margin by service line, confirmed ticket backlog trends, and tested five customer renewals. Outcome: four times multiple with 65 percent cash at completion, short earn-out tied to monthly recurring revenue. Margin lifted two points in eight weeks after standardising quoting and triage.
Commercial Cleaning, Midlands: £2.2m revenue, £270k EBITDA, concentration at 32 percent with a supermarket chain. Diligence confirmed a mid-term renewal window. Price cut by three-quarters of a turn and earn-out linked to renewal of the named account. Vendor handover two days a week for the first 60 days. Concentration down to 20 percent by month four.
E-commerce Components, UAE Free Zone: £3m equivalent revenue, 35 percent gross margin, debtor days at 58. Diligence exposed discount creep and slow-moving stock. Working-capital peg set to trailing average with a separate provision for obsolete lines. Collections cadence reduced debtor days by 10 within two cycles, funding the vendor note out of released cash.
Pull It Together In A Clean Heads Of Terms
Your heads should fit on two pages and convert diligence into structure. State price, cash at completion, deferred amounts, and a capped earn-out tied to simple metrics. Include the peg and what qualifies. Choose completion accounts or locked box with leakage defined. Give yourself 30 to 45 days of exclusivity with milestones, list the remaining diligence items, and set a clear timetable to completion. If you already know a red flag is real, write the hedge into the heads rather than pretending it will fix itself.
Make Your Next Review Faster
If you want a pack you can issue on day one of exclusivity, download the Due Diligence Pack: Financial, Legal & Operational Templates. It includes request lists, call scripts, and a peg calculator so you can run due diligence in 10 days without drowning in noise. Keep it open alongside Mergers & Acquisitions (M&A): The Complete SME Buy & Exit Playbook while you push a live deal.
Key Takeaways
- Run due diligence with a 10-day plan that proves earnings, maps risk, and protects day-two cash.
- Turn findings into price and structure: the peg, short capped earn-outs, vendor notes, and holdbacks.
- Keep month one boring by stabilising billing, comms, and five weekly metrics that predict cash.
FAQ For SME Due Diligence
What should I verify first in due diligence?
Start with the bank and the ledgers. Tie revenue to invoices and cash received, rebuild gross margin by line, and reconcile last month’s closing cash across statements and accounts.
How many customer calls are enough?
Ten short calls, plus two with churned customers, usually expose the truth. Confirm price paid, renewal dates, switching triggers, and what would make them leave.
What is the working-capital peg and why does it matter?
It is the agreed level of net working capital you expect on completion. Set it from trailing averages, list what qualifies, and price slow-moving stock below cost. The peg protects day-two cash better than haggling over a tiny price point.
When should I choose a locked box over completion accounts?
If trading is steady and leakage can be policed, locked box keeps noise down. If trading is volatile or seasonality is sharp, completion accounts are safer. Pick what your model and lender prefer.
How do I deal with a key person risk?
Document a 60-day shadow plan, set retention bonuses tied to deliverables, and reflect the risk in price or structure. If the seller is the rainmaker, haircut the multiple or link part of the earn-out to named renewals.
Can I finish due diligence in 10 days?
Yes, if the data room is tidy and you run a timetable. Focus on finance sanity, customer calls, supplier checks, a quote-to-cash walk-through, and the peg. Hold two chase-downs per week and publish a Friday status note.
What red flags justify walking away?
Unreconcilable cash, undisclosed litigation that threatens a year of profit, falsified contracts, or a single dependency that the seller will not price or hedge. If you cannot run it on Monday, you should not buy it.
Do I need W&I insurance for small deals?
Often not under £5m enterprise value if you have a sensible holdback, vendor note, and tight warranties. If the sector is regulated or claims history is messy, get quotes and compare to the downside.
