If you are considering an exit within the next twelve to twenty-four months, the decisions you make today will determine the outcome you achieve tomorrow. Here are the seven most common mistakes we encounter, and what you should do instead.
Selling a business is one of the most significant financial events most owners will ever experience. Yet the majority approach it with far less preparation than the decision warrants. We have guided businesses through exits at every scale – from seven-figure lifestyle businesses to mid-market M&A transactions – and the mistakes we see are rarely unique. They are predictable, costly, and almost always preventable.
If you are considering an exit within the next twelve to twenty-four months, the decisions you make today will determine the outcome you achieve tomorrow. Below are the seven most common mistakes we encounter, and what you should do instead.
1. Waiting Until You’re Ready to Sell Before Preparing the Business
The mistake: Most business owners begin preparing for an exit only when they have decided to sell. By then, it is often too late to address the structural weaknesses that will depress valuation or complicate due diligence.
Why it matters: Buyers do not pay for potential but instead they pay for proven, de-risked performance. If your financials are inconsistent, your operations are overly dependent on you personally, or your customer concentration is too high, no amount of storytelling will compensate for it at the negotiating table.
What to do instead: Start preparing your business for exit the moment you no longer intend to run it indefinitely. That may be three years out. It may be five. The timeline matters less than the commitment to build a business that could be sold, even if you never intend to do so.
Clean financials, documented processes, diversified revenue, and a management layer that does not require your constant presence – these are not exit strategies. They are the hallmarks of a well-run business.
2. Overestimating What Your Business Is Worth
The mistake: Owners routinely overvalue their business by conflating revenue with value, or by relying on outdated industry multiples that no longer reflect market conditions.
Why it matters: An inflated valuation expectation leads to one of two outcomes: either you price yourself out of serious buyer interest, or you enter negotiations with unrealistic anchors that make it nearly impossible to reach terms. Both waste time, and time is the enemy of any transaction.
What to do instead: Obtain a formal, third-party valuation well in advance of going to market. Not an optimistic back-of-the-envelope estimate from a broker hoping to win your listing – a rigorous analysis that accounts for your sector, your growth trajectory, your margin profile, and the macroeconomic environment.
Understand what buyers in your segment are actually paying, and why. If the number disappoints you, you now have a roadmap for what needs to change before you go to market.
3. Going to Market Without a Clear Exit Strategy
The mistake: Many owners decide to “test the market” without a coherent plan for what success looks like, who the ideal buyer is, or what they will do if the process stalls.
Why it matters: M&A is very much a reputational market. If you go to market half-prepared, word spreads quickly.
Buyers talk. Advisors talk.
A failed process makes the next attempt significantly harder, because serious acquirers will wonder what went wrong the first time.
What to do instead: Define your exit criteria before you engage a single buyer.
What is your minimum acceptable price?
What deal structure are you willing to consider – all cash, earnout, seller financing?
Are you open to staying on in a transitional role, or is a clean break non-negotiable?
Who is the ideal acquirer – strategic, financial, or individual?
The clearer you are on these questions internally, the more control you will have externally.
4. Failing to Diversify Revenue Concentration
The mistake: A business that derives more than 30% of its revenue from a single client, or a narrow set of clients, is inherently riskier to a buyer than one with a diversified base.
Why it matters: Concentration risk is one of the first things buyers assess during due diligence. If losing one or two clients would materially impact revenue, the business is not acquisition-ready. The buyer will either walk, or they will demand a significant discount to compensate for that risk.
What to do instead: Begin diversifying your revenue base at least two years before a planned exit. That may mean broadening your product offering, entering adjacent markets, or simply refusing to allow any one client to exceed 20% of total revenue. It is uncomfortable in the short term — turning down large contracts or deprioritising a whale client — but it is essential for de-risking the business in the eyes of an acquirer.
5. Neglecting Financial Hygiene
The mistake: Inconsistent bookkeeping, personal expenses run through the business, incomplete financial records, or a refusal to separate owner compensation from profit distributions.
Why it matters: It is a proven fact that due diligence is where nearly half of deals die. Buyers and their advisors will scrutinise every line item. If your financials are messy, opaque, or difficult to normalise, you have introduced friction into a process that already requires trust. Friction kills momentum, and momentum is everything in M&A.
What to do instead: Treat your financials the way a public company would. Reconcile monthly. Maintain a clean separation between business and personal expenses. Work with a qualified accountant who understands M&A, not just tax minimisation. If you have been running personal expenses through the business, stop immediately — and if an exit is imminent, prepare detailed normalisation schedules that a buyer’s accountant can verify.
6. Underestimating the Emotional Toll of the Process
The mistake: Owners enter an exit process expecting it to be transactional and clinical. It is rarely either. It is long, intrusive, emotionally exhausting, and often feels personal even when it is not.
Why it matters: M&A processes take longer than anyone expects – often six to twelve months from initial approach to close. During that time, you will be running your business, managing due diligence requests, negotiating terms, and fielding questions that will feel like challenges to your competence. If you are unprepared for the emotional weight of that, you are more likely to make poor decisions under pressure.
What to do instead: Surround yourself with advisors who have done this before – not just technically competent advisors, but those who understand the human side of the process. Lean on your M&A advisor, your lawyer, and your accountant to absorb as much of the operational burden as possible. Set boundaries. Protect time to think. And accept that some level of discomfort is unavoidable. The question is whether you are prepared to endure it in service of the outcome.
7. Choosing the Wrong Advisor (or None at All)
The mistake: Some owners attempt to sell their business without professional representation, believing they can save on advisory fees. Others select an advisor based on the lowest fee structure or the most optimistic projections, rather than on competence and track record.
Why it matters: The difference between a well-advised exit and a poorly-advised one is not marginal – it is often measured in six or seven figures. A skilled M&A advisor does not simply introduce you to buyers. They structure the process, manage the timing, negotiate from a position of strength, and prevent you from making concessions you will regret. The cost of that counsel is almost always recovered several times over in the final sale price.
What to do instead: Engage an advisor early, and choose one with demonstrable experience in your sector and at your transaction size. Ask for references. Ask to see closed deals, not just active listings. Understand their fee structure, but do not optimise for cost – optimise for outcome. A 5% fee on a £3 million exit is far more valuable than a 2% fee on a £2 million exit.
Final Thoughts
The outcome of an exit is determined long before the first offer letter arrives. If you are serious about achieving a successful exit, the work begins now: in your financials, in your operations, in your understanding of what your business is actually worth, and in the team you assemble to guide you through it.
We work with business owners who understand that preparation is not optional. If you are considering an exit in the next twelve to thirty-six months and want to discuss what readiness looks like in practice, we would be happy to speak with you.
About Thireos Consulting Group
Thireos Consulting Group is an advisory firm specialising in exit consulting and M&A for businesses in the mid-market and £1M+ segment. With offices in London and Athens, we provide strategic counsel to business owners preparing for sale, acquisition, or significant growth transition. Our approach is rigorous, discreet, and built on decades of collective experience across global markets.
Contact us: hello@thireos.com
Learn more: Exit Consulting Services
