In any merger or acquisition, the deal price is the number everyone negotiates. The deal structure is the number that determines how much each party actually keeps. Tax planning in M&A is not a post-closing exercise. It is a deal-shaping discipline that starts before the letter of intent is signed and influences everything from purchase price allocation to earnout mechanics.
The difference between a tax-efficient structure and a default structure on a $5 million transaction can easily exceed $500,000 in total tax impact across both parties. For cross-border deals between the U.S. and Canada, the complexity and the stakes increase further.
This guide covers the key tax decisions buyers and sellers face, the due diligence items that derail deals when overlooked, and the planning strategies that optimize after-tax outcomes.
Why Tax Planning Must Start Before the LOI
By the time a letter of intent is signed, the deal's economic terms are largely set. But the tax structure, which determines how those economics translate to after-tax results, is often undeveloped. Buyers and sellers who engage tax advisors after signing the LOI frequently discover that the agreed price does not account for structural tax costs that change the effective value of the deal.
Tax planning at the LOI stage allows both parties to model the transaction under different structures, understand the tax impact on each side, and negotiate terms that reflect the actual after-tax economics.
Asset Purchase vs Stock Purchase
Tax Implications for the Buyer
An asset purchase gives the buyer a stepped-up tax basis in the acquired assets equal to the purchase price. This means the buyer can depreciate and amortize the acquired assets based on what they paid, generating tax deductions over the useful life of each asset category. For a $3 million asset purchase, the buyer may allocate $500,000 to equipment (5 to 7 year depreciation), $200,000 to a customer list (15 year amortization), and $1.5 million to goodwill (15 year amortization), creating significant tax shields over the next 5 to 15 years.
In a stock purchase, the buyer inherits the target's existing tax basis, which is typically far lower than the purchase price. No stepped-up basis is available, and the buyer receives limited depreciation and amortization benefits from the acquisition.
Tax Implications for the Seller
The buyer's preference for an asset purchase often conflicts with the seller's preference for a stock sale. In an asset sale of a C Corporation, the corporation recognizes gain on the sale of assets (taxed at the corporate rate), and the shareholders recognize gain on the liquidating distribution (taxed at the capital gains rate). This creates a double tax that can consume 40% or more of the proceeds.
In a stock sale, the shareholder sells their ownership interest and pays capital gains tax at the individual level, typically 20% for long-term holdings plus the 3.8% Net Investment Income Tax. For S Corporations, partnerships, and LLCs, the entity structure affects whether the asset-level gain is taxed once or twice.
Structuring an M&A deal? The tax decisions made before closing determine how much you keep. Schedule a tax planning session with TYM Consulting.
The 338(h)(10) Election
When both parties want to bridge the gap between asset purchase tax treatment and stock purchase simplicity, the Section 338(h)(10) election offers a solution for S Corporations and certain consolidated group members. This election treats a stock purchase as a hypothetical asset sale for tax purposes, giving the buyer a stepped-up basis while allowing the transaction to close as a stock purchase.
Both buyer and seller must consent to the election. The seller reports the transaction as an asset sale, so the election works best when the seller's tax cost is manageable (often the case for S Corps where gains pass through at individual rates without double taxation).
Due Diligence Tax Issues That Derail Deals
Tax due diligence uncovers liabilities that the buyer will inherit in a stock purchase or that affect the value of assets in an asset purchase. Critical items include unfiled or incorrectly filed tax returns in any jurisdiction, outstanding IRS or state audit assessments, improper worker classification (employees treated as contractors), underpaid sales tax or uncollected use tax, net operating loss carryforwards that may be limited post-acquisition under Section 382, and transfer pricing exposures in cross-border operations.
Any of these issues can reduce the target's value, require indemnification provisions, or prompt escrow holdback requirements in the purchase agreement.
Purchase Price Allocation
IRS Section 1060 requires the purchase price in an asset acquisition to be allocated among the acquired assets following a priority hierarchy. Cash and near-cash items are allocated first, followed by actively traded personal property, accounts receivable, inventory, other tangible and intangible assets, and finally goodwill and going concern value.
The allocation directly affects the buyer's depreciation and amortization schedules and the seller's character of gain (ordinary income versus capital gain). Both parties must report the same allocation on Form 8594, which the IRS uses to identify inconsistencies.
Earnout and Deferred Payment Structures
Earnouts tie a portion of the purchase price to the business's future performance. While they bridge valuation gaps, they create complex tax timing issues. Under the installment method, the seller defers gain recognition until payments are received. The buyer must determine the present value of earnout obligations for allocation purposes.
Character classification matters as well. Earnout payments may be treated as purchase price adjustments (capital gain) or as compensation (ordinary income) depending on how they are structured and whether the seller continues working for the business.
Cross-Border M&A Tax Considerations
Deals involving U.S. and Canadian entities add treaty analysis, withholding tax, and transfer pricing dimensions. Key considerations include whether the acquisition creates a permanent establishment, withholding tax on cross-border payments (dividends, royalties, management fees), Canadian capital gains treatment for the seller, and post-acquisition intercompany pricing that meets both IRS and CRA standards.
TYM Consulting, operating from both Toronto and Miami, provides cross-border M&A tax advisory that addresses both jurisdictions simultaneously.
Post-Closing Tax Integration
After closing, the buyer must integrate the target's tax compliance into their existing structure. This includes filing short-period returns for the target, implementing the purchase price allocation in the buyer's accounting system, establishing transfer pricing policies for intercompany transactions, and ensuring payroll, sales tax, and state registrations reflect the new ownership.
M&A transactions are where tax planning has the highest dollar impact. Contact TYM Consulting for deal structuring and tax advisory support.