You closed the acquisition: the finance mistakes that quietly erase the deal's value

The deal closed, and the hard part started

The biggest finance mistakes after an acquisition are losing control of cash in the acquired company, running two sets of books that never get reconciled into one, losing the people who understood the acquired company's numbers, and treating integration as something to deal with after the excitement fades. Close behind are tax and reporting errors around the purchase itself, and synergies that were promised in the deal model but never tracked. Each of these is avoidable with a plan that starts before closing.

I have led post-merger integrations and guided finance departments through acquisitions, sales and high-growth expansions, including deals with operations in the United States and Asia. As a partner at ECFO I work with buyers in Dallas and elsewhere on the finance side of integration. What follows is the list I wish every buyer read before signing, written in the order the problems usually appear.

Mistake one: no plan for the first day

On the day after closing, someone has to know who can approve payments, who can move money, which bank accounts exist and who has access to them, and how payroll will run. When those questions are answered in the first week rather than before closing, the result is confusion at best and losses at worst. Vendors get paid twice or not at all, payroll runs late, and former owners or departing staff retain access they should no longer have.

A day-one finance plan does not need to be elaborate. It needs to name the people, the accounts and the approval limits, and it needs to be agreed before the deal closes. It also helps to decide who will be the single finance point of contact for the acquired company's staff, so that questions about payments, expenses and payroll go to one person instead of being answered differently by whoever happens to be asked.

• List every bank account and update signatories and online access on day one.
• Set approval limits for payments and purchases in the acquired company.
• Confirm how and when payroll and payroll taxes will be processed.
• Identify critical vendors and customers and who will speak to them.
• Freeze changes to vendor bank details until verification procedures are in place.

Mistake two: two sets of books that never merge

The acquired company usually arrives with its own chart of accounts, accounting system, close calendar and habits. If nobody maps those to the buyer's structure, the combined company spends months producing reports that cannot be compared. Revenue may be recognized differently, expenses categorized differently and intercompany balances left unreconciled. Management loses the ability to see whether the acquisition is performing.

Pay particular attention to intercompany transactions once the two businesses start trading with each other. Sales, shared costs and loans between the entities have to be recorded on both sides and eliminated in the consolidated results, or the combined company will overstate its revenue and costs.

The fix is to decide early on the target chart of accounts, reporting calendar and accounting policies, then map the acquired company's history to them. Whether the acquired company eventually moves onto the buyer's system is a separate decision, and often a good one, but it should follow the policy decisions rather than replace them. My guide on outgrowing QuickBooks and switching systems explains why a new system run on unchanged processes rarely helps.

Mistake three: losing the people who knew the numbers

In smaller acquisitions, much of the acquired company's financial knowledge lives in a few heads: the long-serving bookkeeper, the controller who built the spreadsheets, the owner who negotiated every customer price. If those people leave in the first months, the buyer loses the ability to explain the numbers it just paid for. Undocumented processes become guesses.

Identify these people before closing, make sure they have a reason to stay through the transition, and use that time to document what they know. Developing and retaining the acquired finance team is part of the integration, not an afterthought. In my experience, the cost of keeping a key person through the first year is small compared with the cost of reconstructing what they knew.

Mistake four: cash and working capital left unmanaged

Acquisitions are often financed with debt, and the combined business has to service it from day one. Yet the acquired company's receivables, inventory and payables frequently run on old habits for months. Collections slow during the transition because customers are unsure who to pay, and inventory practices diverge from the buyer's. The result is a cash squeeze in a business that looked healthy in diligence.

Put the acquired company on the buyer's cash forecast immediately, at least weekly in the first months. Watch the working capital true-up in the purchase agreement as well; disputes over the closing balance sheet are common, and the buyer's finance team needs to be ready with its own numbers. The quality of the diligence work matters here, which is why I cover working capital in getting the financials ready for due diligence.

• Add the acquired company to a weekly cash forecast from the first week.
• Tell customers clearly where and how to pay after closing.
• Review inventory levels and purchasing approvals.
• Prepare your own closing balance sheet for the working capital adjustment.
• Track debt covenants for the combined business monthly.

Mistake five: tax and purchase reporting done late or inconsistently

The way an acquisition is structured and how the price is allocated have tax consequences for years. In an asset purchase, the price has to be allocated among the assets acquired, including goodwill. The IRS says both the buyer and the seller use Form 8594 to report the sale of a group of assets that makes up a trade or business when goodwill or going concern value attaches, or could attach, to those assets. When the two sides report the allocation differently, it can create problems for both, so the allocation is best agreed in the purchase agreement and reflected consistently.

This is an area for your tax advisor and attorney; my role is to make sure the finance records, fixed asset registers and opening balance sheet reflect what was agreed. If the acquired company has foreign operations, related-party pricing and cross-border tax structures need to be reviewed early as well, because they are much harder to unwind after the fact.

Mistake six: synergies nobody measures

Most acquisition models assume savings or growth from combining the businesses: shared purchasing, consolidated overhead, cross-selling. Those numbers helped justify the price. After closing, they are often forgotten, or the cost of achieving them is underestimated. A year later nobody can say whether the deal delivered what it promised.

Turn each synergy in the deal model into a specific action with an owner, a date and a way to measure it in the monthly reports. Track integration costs separately so they do not hide inside normal operating expenses. Report progress to the owners or board regularly. This is not bureaucracy; it is the only way to know whether the acquisition is working and to correct course while there is still time.

Be honest about the synergies that turn out not to exist. Some assumptions in every deal model prove wrong once you see the business from the inside. Recognizing that early and adjusting the plan is far better than carrying a target nobody believes, because an unrealistic target distorts budgets, bonuses and the decisions built on them.

Mistake seven: controls that weaken in the transition

Integration periods are when controls are weakest. Roles change, people leave, systems are half-migrated and everyone is busy. Payments get approved by whoever is available, reconciliations slip and access rights accumulate. Fraud and errors both thrive in that environment, including payment fraud that targets companies changing vendors and bank details.

Set out the minimum controls for the acquired company in the first month: who approves what, who reconciles what, and how vendor bank changes are verified. Then build toward the full control environment over the following months. My guide to internal controls for a growing company covers the core set.

A simple integration timeline that works

Every integration is different, but the sequence that works is consistent: control first, visibility second, consolidation third. Before closing, agree the day-one plan. In the first weeks, secure cash and access and get the acquired company onto the cash forecast. In the first months, map the books, align policies and report the combined results. After that comes system migration, process redesign and synergy delivery. The U.S. Small Business Administration recommends that buyers conduct a thorough, objective investigation and involve an attorney and an accountant; integration planning is the natural continuation of that diligence.

• Before closing: day-one finance plan, key people identified, policies chosen.
• First weeks: bank access, approvals, payroll, weekly cash forecast.
• First months: chart of accounts mapping, consolidated reporting, closing balance sheet.
• Later: system migration, process redesign, synergy tracking and full controls.

Bringing in integration leadership

Many buyers are running their own business at full speed and do not have spare finance capacity for an integration. That is when an interim or fractional CFO focused on the integration earns the fee: someone to lead the day-one plan, manage the acquired finance team, align the books and report progress, while your existing team keeps the core business running.

If you are planning an acquisition or have recently closed one, I am glad to talk through where the integration stands. I work with companies across the Dallas–Fort Worth area and remotely, and with buyers whose targets have suppliers or operations in China and Southeast Asia.

Questions people ask me