12 Months Before You Sell: The Preparation That Actually Moves the Number

Advised by Leo Meggitt, Managing Director, Mastella Advisory. Last updated August 2026.

Ask any experienced UK M&A advisor which owners consistently achieve the strongest sale outcomes and you get a version of the same answer: the ones who started preparing 12 to 24 months before they went to market. Not the ones with the best businesses. Not the ones in the hottest sectors. The ones who did the readiness work.

This piece walks through the specific preparation work that most reliably changes the outcome for UK lower mid-market owners. Everything below is what we do inside a formal exit planning engagement; it is also what motivated owners can start on their own, six to twelve months before engaging any advisor.

The order below is roughly the order of return-on-effort. Start at the top.

1. Financial hygiene

The single highest-return item on the pre-sale list. Buyers will rebuild your EBITDA from your management accounts during diligence. Every adjustment you make (owner salary normalisation, personal expenses, one-off items, pro-forma adjustments) will be tested. Owners who arrive with a defensible EBITDA bridge already documented, backed by supporting evidence, keep the value they claim. Owners who leave adjustments undocumented lose them.

Practical steps in the 12 months before market:

• Three years of monthly management accounts that reconcile cleanly to statutory accounts. Not just the annual numbers. Monthly, so buyers can see seasonality and trend.
• An adjusted EBITDA bridge, documented and evidenced. Owner discretionary items (above-market salary, personal expenses, family member compensation). Genuine one-offs (M&A costs, restructuring, one-time write-downs). Non-trading items (grant income, insurance recoveries). Each adjustment supported by contemporaneous evidence.
• Working capital normalisation. The trailing 12-month average of working capital, ideally reviewed by your own accountants before the buyer's diligence team gets there. Working capital normalisation is the single most disputed line item in UK lower mid-market completion mechanics.
• KPI reporting buyers will recognise. Revenue by customer, revenue by contract type, gross margin by product/service line, pipeline coverage, sales-cycle metrics. Whatever is standard in your sector, buyers expect to see. If you cannot produce these numbers on request, buyers assume you are not managing to them.

Where owners have historically run their business on annual accounts alone, this piece of work often takes 6 months to do properly. Start early.

2. Customer concentration

Customer concentration is the single most-cited diligence flag across every sector we cover. The rule of thumb in the UK lower mid-market is that no single customer should represent more than 10 to 15% of revenue. Concentrations above 20% typically discount the multiple. Concentrations above 30% narrow the buyer pool materially. Concentrations above 50% often kill deals outright.

If your concentration is high, you have two options in the 12 to 24 months before going to market: broaden the book (organically or via acquired customers) or document the depth of the anchor relationships properly so they can be defended rather than discounted. The second option is often more realistic and produces surprisingly strong results.

Documentation of anchor customer depth includes:

• Length of relationship (years, ideally decades)
• Contractual position (multi-year contracts, exclusivity, change-of-control clauses)
• Switching cost from the customer's perspective (technology integration, operational integration, embedded processes)
• Multiple stakeholder relationships within the customer (not just one champion)
• Historic renewal rates and rate rises
• Reference-callable senior contacts at the customer

The same 30% concentration with deep documented relationships trades materially differently from 30% concentration on rolling 12-month contracts with a single named champion.

Sector-specific concentration norms differ. For example, on specialist manufacturing single OEM concentrations of 25 to 40% are common; on MSPs premium multiples typically require top-client concentration below 10%.

3. Management team depth and founder dependency

The most overlooked piece of pre-sale work in the UK lower mid-market. Buyers want to see a business that can survive the owner's departure. If you are personally the load-bearing structure for customer relationships, technical judgement, supplier negotiations, or major operational decisions, that is a discount to the multiple. Usually a large one.

The 12 to 18 month project: build out a credible second-in-command, document founder-held customer relationships and gradually transition them to the wider senior team, and be able to point to specific decisions the senior team has made without your involvement. Buyers ask "what would happen if the owner left tomorrow?" and expect a serious answer.

Specific tests buyers apply:

• Who signs off on customer proposals above £X?
• Who has the primary relationship with each of the top 10 customers by name?
• Who runs weekly and monthly management meetings when the owner is on holiday?
• What are the KPIs the senior team is managed against, and are they consistently reviewed?
• Are there written job descriptions, targets and development plans for the senior team?

Owners whose answer to these questions is "well, I do most of it" have a founder-dependency problem. Owners who can point to named individuals with clear responsibilities and demonstrable autonomy have a business the buyer can imagine owning.

4. Contract review and change-of-control

Buyers will map every material customer contract for change-of-control clauses, assignment provisions, exclusivity terms and open re-tender dates. They will do the same for material supplier contracts, IP licences, property leases and any joint venture arrangements.

Change-of-control clauses in particular deserve early attention. A clause that gives a major customer the right to walk when ownership changes is not automatically a deal-killer, but it is a diligence point the buyer will want a plan for. That plan is easier to construct before the deal is announced than during exclusivity.

The 12-month project: pull every material contract, catalogue the change-of-control, assignment, notification and consent requirements, flag any customer contracts approaching renewal within 18 months of expected completion, and identify any contracts where language is unusual or worth renegotiating pre-sale.

Talk to us

If you are 12 to 24 months from a target exit and want an independent view on where your preparation stands, book a 45-minute confidential conversation. Our exit planning service covers this readiness work end to end.

5. Key-person risk beyond the owner

The senior team below the owner. Which two or three individuals, if they left in the six months post-completion, would materially damage the business? Buyers ask this in explicit form during diligence. Their answer drives the retention arrangements they insist on at signing. Yours, thought through in advance, tells you where lock-ins, retention bonuses or equity arrangements need to be in place before those team members are asked to accept them under transaction pressure.

Standard mechanisms for retaining key people through a transaction:

• Restrictive covenants tightened to reflect market norms (non-compete typically 12 to 18 months, non-solicit typically 12 to 24 months)
• Retention bonuses vesting 6 to 24 months post-completion
• Equity or share option arrangements creating rollover-adjacent participation in the eventual exit
• Clear post-sale role definition with defined authority and remuneration

All of these are more credible when arranged 6 to 12 months before a transaction than in the final weeks of a process. The pre-sale runway matters.

6. IP protection and ownership

Every material piece of IP in the business (code, brand, methodology, data, trademarks, patents) should be owned by the company with a clean chain of assignment from every contractor and former employee who touched it. Historic IP built by contractors under unclear ownership terms is one of the most common late-stage diligence flags. It rarely kills a deal, but it consistently costs weeks of remediation and sometimes chunks of consideration.

Practical checklist for the 12 months before market:

• Trademark register searches on brand assets (UK IPO and, if relevant, EUIPO and USPTO)
• Domain name inventory with named registrant and expiry dates
• Employment contracts confirming employee IP assignment
• Contractor and consultant agreements confirming IP assignment
• Open-source licence audit for any code assets (particularly GPL/AGPL exposure)
• Any joint IP arrangements with customers or partners, documented

Deeper coverage of IP-heavy sub-sectors sits under our tech-enabled services pillar.

7. Working capital normalisation (in depth)

Called out under financial hygiene above but worth its own section because it drives more late-stage disputes than almost any other line item. The buyer will set a "target working capital" at completion, and any deviation from that target adjusts the consideration payable. Getting the target wrong (or getting the calculation methodology wrong) can cost owners hundreds of thousands of pounds at completion.

Standard approach: 12-month rolling average working capital, ideally reviewed by your own accountants and presented to the buyer with supporting analysis. Anomalous months (major one-time customer receipt, one-time supplier payment, unusual stock build) flagged and normalised. Seasonality documented so buyers cannot claim the completion month is "unusually favourable" to the seller.

Owners running businesses with high seasonality (retail, seasonal services, project-based) should engage on working capital methodology with their accountants at least 6 months before going to market.

8. Corporate housekeeping (PSC register, shares, articles)

The unglamorous items that trip owners up at legal diligence:

• PSC (Persons with Significant Control) register. Required under Companies Act 2006 and CA 2006 Schedule 1A; must be accurate at Companies House and consistent with internal records. Historically overlooked; now often diligenced.
• Share register and cap table. Every share issue, transfer, option grant and buyback correctly recorded, with supporting documentation.
• Articles of association. Reviewed for any unusual provisions, share class rights, or drag/tag arrangements that pre-date current owners' understanding.
• Board minutes. Complete, signed, filed, evidencing all major corporate decisions.
• Statutory registers. Members' register, directors' register, secretary's register (where applicable) all up to date.
• Confirmation statement and annual accounts. Filed on time; any late filings noted and reason documented.

None of this individually is high-stakes; collectively, sloppy corporate housekeeping signals to buyers that the seller runs a loose ship. A defensive corporate cleanup takes 2 to 4 weeks with a decent company secretary or corporate lawyer.

9. Tax structuring

Pre-sale tax structuring is one of the highest-ROI activities in any exit but many of the most useful interventions require 12 months of runway before completion, and some (particularly around share reorganisations, family trust structures, and BADR positioning) require longer. Waiting until a specific deal is on the table typically closes off the highest-value options.

The 2026 UK tax environment has shifted materially: BADR rate has risen from 10% to 18% over the last three years, the £1M lifetime limit remains, and general CGT rates have moved. What worked as pre-sale planning in 2022 is different from what works in 2026. Engage a transaction-tax specialist at least 12 months before target completion.

10. Property and freehold strategy

Where the business owns freehold property (typical in plant hire, warehousing, care, industrial coatings and several other sectors), decide the property strategy before going to market. Options include: retain freehold personally and lease to the buyer, sell freehold as part of the bundle, or sell the operating business to one buyer and the freehold to another (OpCo/PropCo, worth exploring for freehold-heavy portfolios where total proceeds may improve).

Each option has different tax implications and different buyer-pool implications. The choice should be made with tax advice in place, not defaulted to.

11. Reference-callable customers, suppliers, employees

Buyers doing serious diligence will request reference calls with named customers, key suppliers, and (occasionally) former employees. Line these up in advance. Identify 3 to 5 customers who genuinely value the relationship and would speak positively; the same for suppliers; and (with care) 1 to 2 former employees who left on good terms and understand the business well. Having these ready to hand accelerates diligence and signals professionalism.

12. Life-after-exit planning

The final item on the list is not about the business at all. It is about you. Owners who cannot answer "what does the first 12 months post-completion look like for me personally?" routinely find themselves accepting terms during negotiation (post-sale role, earn-out linkage to their continued involvement, non-compete scope) that do not match what they actually want. Getting clear on the post-exit plan before running the process is the single most reliable way to make good decisions inside it.

Specific questions worth answering:

• What am I doing operationally in months 1 to 3 post-completion?
• What am I doing in months 4 to 12?
• What do I want the buyer to expect of me?
• What am I willing to have in the non-compete: geography, sector, time?
• What am I willing to have in the non-solicit: which employees, which customers?
• What does my personal financial life look like post-completion, and does the structure of consideration (cash vs deferred vs rollover) match my actual liquidity needs?

These questions are easier to answer 12 months out than 12 days out.

The compound effect

The headline outcome of a proper 12-month readiness period is rarely a single dramatic uplift. It is the compound effect of doing seven or eight things well that owners running a cold process tend to do badly or not at all. Deals that closed at or above headline expectation were almost always preceded by structured preparation work; deals that re-traded at completion were almost always run cold.

If you are 12 to 24 months from a target exit and want the readiness work done properly, our exit planning service covers all twelve items above alongside your accountants and lawyers. If you are simply thinking about it and want a first honest conversation on what the runway looks like, book a 45-minute confidential conversation. Forty-five minutes, no obligation, and you will leave with a clearer view of where your business genuinely stands against buyer expectations.