A company merger works by legally combining two or more businesses into one surviving entity through a sequence of steps: the buyer investigates the target, the parties negotiate and sign a merger agreement, each company’s board and shareholders approve it, federal and state regulators clear it, the companies file Articles of Merger with the state, and the surviving entity absorbs the other’s assets, contracts, and liabilities. The whole process usually takes months, and the choices made early — especially about deal structure — dictate the tax bill, which contracts survive, and how much regulatory scrutiny follows.
Choosing the Structure
The first real decision in any merger is structural, because that choice controls tax treatment, which contracts carry over, and how antitrust regulators will look at the deal. Structures generally fall into a few familiar categories:
- Horizontal: two competitors in the same industry combine. A grocery chain buying another grocery chain is the classic example, and these draw the heaviest antitrust review because they directly reduce competition.
- Vertical: two companies at different points in the same supply chain combine, such as a manufacturer joining with its parts supplier.
- Conglomerate: two businesses with unrelated products or markets combine, diversifying the resulting company across industries.
- Market extension: two companies selling the same products in different geographies combine, expanding each other’s customer base.
- Product extension: two companies in the same market with complementary but non-competing products combine.
Reverse Triangular Mergers
Many larger transactions use a reverse triangular structure. The buyer creates a temporary subsidiary for the sole purpose of acquiring the target. That subsidiary merges into the target, the subsidiary disappears, and the target survives as a wholly owned subsidiary of the buyer. Because the target technically survives, its contracts, licenses, and permits generally stay intact. The buyer’s other assets also stay insulated from the target’s existing liabilities, since the subsidiary took on that risk rather than the parent.
Short-Form Mergers
When a parent already owns 90 percent or more of a subsidiary’s stock, most states allow a short-form merger. The parent’s board can approve it on its own, with no shareholder vote from either side. The exact ownership threshold varies by state, but 90 percent is the most common cutoff.
Due Diligence
Before signing anything, the buyer investigates the target’s finances, legal exposure, and operations. This is where prices get renegotiated and, occasionally, where deals collapse. It matters more than in a typical asset purchase because of a rule discussed later on: in a statutory merger, the surviving company inherits everything the disappearing company owed, whether or not the merger agreement mentions it.
A thorough review usually covers:
- Financial records: bank statements, debt agreements, credit lines, and trial balances going back at least three years, looking for hidden liabilities and irregular revenue patterns.
- Tax history: federal and state returns, property tax records, credits claimed, and any unresolved disputes or aggressive filing positions.
- Legal exposure: pending or threatened litigation, regulatory investigations, environmental issues, consent decrees, and settlement obligations.
- Intellectual property: patents, trademarks, copyrights, licensing agreements, and any active IP disputes.
- Human resources: employee contracts, benefit plan obligations, retirement plan funding, pending discrimination claims, and union agreements.
- Contracts and customers: key agreements, revenue concentration, and change-of-control provisions that could let counterparties walk after closing.
What you don’t find during due diligence, you find after closing, when there is no room left to negotiate.
The Merger Agreement
The merger agreement is the document that governs the entire transaction. It names the participating companies, identifies which entity survives, spells out how stock in the disappearing company will be converted into equity or cash in the surviving one, and sets the closing timeline. For significant deals, this document runs dozens or hundreds of pages after intensive negotiation.
Interim Operating Covenants
Weeks or months can pass between signing and closing, so the agreement restricts what the target can do in the meantime. These interim covenants usually require the target to run its business normally: no significant new debt, no dividends, no changes to executive compensation, no major contracts started or terminated, and no large capital expenditures without the buyer’s written consent. Violating these can let the buyer walk away, demand a price adjustment, or seek damages.
Board and Shareholder Approvals
Each company’s board of directors must formally approve the merger by resolution. Shareholders then generally vote on it. The threshold varies by state, but a simple majority or two-thirds supermajority of outstanding shares is common. Documentation of the vote becomes part of the permanent corporate record. Short-form mergers are the exception, since the parent’s overwhelming ownership makes a shareholder vote unnecessary.
Appraisal Rights for Dissenting Shareholders
Shareholders who vote against the merger aren’t necessarily stuck with the deal’s price. Under most state laws, dissenters can exercise appraisal rights: they refuse the merger consideration and petition a court to determine the fair value of their shares. If the court finds the shares worth more than the merger price, the company pays the difference. The process is slow and expensive, and the court can appraise the shares at less than the merger price. Preserving the right typically requires strict procedural steps, including filing an objection before or during the shareholder vote.
Antitrust and Regulatory Review
Federal antitrust review runs on two statutes. The Clayton Act prohibits any acquisition where the effect could be to substantially reduce competition or tend to create a monopoly in any market or region.1Office of the Law Revision Counsel. 15 USC 18 – Acquisition by One Corporation of Stock of Another The Federal Trade Commission and the Department of Justice share enforcement authority, and both agencies actively challenge deals they believe cross that line.2United States Department of Justice. 2023 Merger Guidelines
The Hart-Scott-Rodino Antitrust Improvements Act requires companies to notify the FTC and DOJ before closing deals that exceed certain dollar thresholds.3Federal Trade Commission. Hart-Scott-Rodino Antitrust Improvements Act of 1976 For 2026, the minimum size-of-transaction threshold is $133.9 million, effective February 17, 2026, with a separate higher threshold of $535.5 million applying to certain transactions involving smaller parties. These figures adjust annually based on gross national product changes. Filing fees are substantial, starting at $35,000 for the smallest reportable deals and scaling up to $2.46 million for transactions worth $5.869 billion or more.4Federal Trade Commission. New HSR Thresholds and Filing Fees for 2026
After filing, the parties enter a mandatory waiting period during which they cannot close. If either agency identifies competitive concerns, it can seek a court order to block the deal or demand structural changes, such as divesting certain business units, before allowing it to proceed.5Federal Trade Commission. Premerger Notification Program
Federal review isn’t the only layer. State attorneys general can independently investigate and challenge mergers that threaten competition or consumer welfare within their borders, and they frequently coordinate with the FTC and DOJ on major investigations.6Federal Trade Commission. Protocol for Coordination in Merger Investigations Regulated industries face additional scrutiny: banking mergers require approval from the OCC, Federal Reserve, or FDIC depending on the charter; insurance mergers go through state insurance departments; and hospital or health care consolidations often trigger separate state review of charitable trust obligations, certificate-of-need requirements, or dedicated health care transaction processes.
Tax Structure
How the deal is structured determines whether shareholders face an immediate tax bill or defer their gains. The Internal Revenue Code identifies several types of corporate reorganizations that qualify for tax-free treatment under Section 368.7Office of the Law Revision Counsel. 26 USC 368 – Definitions Relating to Corporate Reorganizations The three most relevant for mergers are:
- Type A (statutory merger): one corporation acquires all of the target’s assets through a state-law merger and the target ceases to exist. Payment can mix stock and cash, but a substantial portion must be stock to maintain what the IRS calls continuity of interest.
- Type B (stock-for-stock): the acquiring company exchanges solely its own voting stock for at least 80 percent control of the target. No cash or other consideration is allowed.
- Type C (asset acquisition): the acquiring company uses its voting stock to buy substantially all of the target’s assets, with limited non-stock consideration permitted.
When a merger qualifies under one of these types, shareholders who receive stock in the surviving company generally don’t recognize a taxable gain at the exchange. Their basis carries over, and they pay tax only when they eventually sell. Shareholders who receive cash or other non-stock consideration, sometimes called boot, owe tax on that portion immediately. If the merger doesn’t meet the Section 368 requirements, the transaction is fully taxable, and target shareholders owe capital gains tax on the difference between what they receive and their original cost basis. For a large shareholder, the gap between a tax-free and taxable deal can be millions of dollars.
Filing the Articles of Merger
Once every approval is secured, the companies file a formal document with the state, usually called Articles of Merger or a Certificate of Merger, to make the combination legally effective. The filing requires the exact legal names and state-issued identification numbers for every participating entity, the name of the surviving entity, the effective date, and a statement confirming that the required board and shareholder approvals were obtained.
Accuracy in this filing matters more than it might appear. The surviving entity field determines which company inherits every right, contract, and obligation, and an error in names or ID numbers can delay the filing or create ambiguity about which company actually survived. State filing fees for merger documents generally run between $35 and $100 for a standard corporation, though some states charge more for complex entities or expedited processing. Processing times range from a few business days for online filings to several weeks for paper submissions. Once approved, the merger is legally complete as of the effective date stated in the filing.
After the Merger Closes
Filing the Articles is the legal finish line, but the surviving entity’s obligations start immediately.
Employer Identification Number
If the merger creates an entirely new corporation, that entity must apply for a new EIN from the IRS. If one of the original companies survives and absorbs the other, the surviving company keeps its existing EIN and no new application is needed.8Internal Revenue Service. When to Get a New EIN Getting this wrong causes problems with tax filings, payroll, and bank accounts.
SEC Disclosure
Publicly traded companies must file a Form 8-K with the Securities and Exchange Commission reporting the completed merger under Item 2.01 (Completion of Acquisition or Disposition of Assets). The filing is due within four business days after closing and must describe the assets involved, the consideration paid, and the identity of the parties.9U.S. Securities and Exchange Commission. Form 8-K Current Report
Successor Liability
In a statutory merger, the surviving company assumes all of the disappearing company’s liabilities by operation of law. Every pending lawsuit, unpaid debt, environmental cleanup obligation, warranty claim, and contractual commitment transfers automatically, whether or not the merger agreement mentions it. You cannot contract your way out of successor liability in a true merger, which is why the due diligence work described earlier is so important.
WARN Act and Employee Impacts
If the merger triggers plant closings or large-scale layoffs, the federal Worker Adjustment and Retraining Notification Act requires covered employers to give affected employees at least 60 calendar days’ written notice before the event.10Office of the Law Revision Counsel. 29 USC Chapter 23 – Worker Adjustment and Retraining Notification The Act applies to employers with 100 or more full-time workers and is triggered when a single-site closure or layoff affects 50 or more employees within a 30-day period. Notice must also go to the state dislocated worker unit and the chief elected official of the local government where the closing or layoff occurs. Employers who violate the WARN Act can be liable for up to 60 days of back pay and benefits for each affected employee, plus a civil penalty of up to $500 per day for failing to notify local government.11Office of the Law Revision Counsel. 29 USC 2104 – Administration and Enforcement of Requirements Limited exceptions exist when the employer was actively seeking financing that would have prevented the closure, when business circumstances were genuinely unforeseeable, or when the event resulted from a natural disaster.
Retirement plans also need attention. The acquired company’s 401(k) or similar plan can be terminated before closing, merged into the buyer’s existing plan, or maintained separately. Each option carries different administrative burdens and tax consequences. When a plan is terminated, all employee accounts fully vest immediately, and participants can roll their balances into another qualified plan or an IRA. When plans are merged, the buyer’s advisors should review the target plan’s compliance history first, because inheriting a plan with existing qualification problems can jeopardize the buyer’s own plan.
Licenses and Permits
The surviving entity should inventory every business license, industry permit, and government registration held by either company. Some transfer automatically by operation of law in a statutory merger. Others, particularly professional licenses, liquor licenses, and certain industry-specific permits, require new applications or transfer approvals from the issuing agency. Letting a critical license lapse during the transition can shut operations down, so building the license inventory during due diligence and assigning someone to manage transfers after closing is worth the effort.