Deferred tax in M&A refers to the deferred tax assets (DTAs) and liabilities (DTLs) that an acquirer must recognize in a business combination on the differences between the book (accounting) basis and the tax basis of the assets acquired and liabilities assumed. It is one of the more technical — and easily mishandled — parts of acquisition accounting, governed by ASC 805 together with the income-tax standards (ASC 740 / IAS 12).
Why deferred taxes arise in a deal
The issue is most acute in a stock acquisition treated as tax-free or with carryover tax basis. In acquisition accounting, the acquirer steps the acquired assets up to fair value for book purposes (the PPA) — but in a carryover-basis stock deal, the tax basis does not step up. That gap between a high book basis and a low tax basis creates a deferred tax liability:
A book value above tax basis means future book depreciation/amortization is not tax-deductible, so more tax will be paid later → a DTL today.
Conversely, where tax basis exceeds book basis (or the target brings deductible attributes), a deferred tax asset arises.
The goodwill "gross-up"
A counterintuitive consequence: recognizing a DTL on stepped-up intangibles in a stock deal increases goodwill. Because the DTL is an additional liability assumed, the net identifiable assets fall, and the residual goodwill rises — the so-called "goodwill gross-up." (Goodwill itself generally gets no offsetting deferred tax in a non-deductible-goodwill deal, which is part of why this works the way it does.) This is a classic area where naïve modeling understates the goodwill a stock deal will produce.
Deferred tax assets and valuation allowances
Acquired DTAs — including those from the target's net operating losses (NOLs), credits and deductible temporary differences — are recognized at fair value, but only to the extent they are more likely than not to be realized. If realization is doubtful, a valuation allowance reduces the DTA. Note that the usability of acquired NOLs is separately limited by IRC §382 after an ownership change — a tax constraint that the accounting must reflect.
Asset deals differ
In an asset deal (or a §338(h)(10)-elected stock deal), the tax basis does step up alongside book basis, so the book–tax gap — and the resulting deferred taxes — is much smaller. This is one of the many ways the tax structure of a transaction flows directly into its accounting.
Why it matters
Deferred tax mechanics affect the goodwill recorded, the net assets on the opening balance sheet, and the combined company's effective tax rate going forward. Getting them wrong misstates the PPA and future earnings, which is why deferred tax is a core part of the deal accountant's and tax adviser's post-close work and of tax due diligence.
See also
- ASC 805 — Business Combinations — The U.S. GAAP standard governing accounting for business combinations. Largely converged with IFRS 3 since 2008.
- Purchase price allocation — The process of assigning an acquisition’s price to the assets and liabilities acquired.
- Goodwill — The intangible asset recorded when a buyer pays more than the fair value of net assets.
- NOL preservation (Section 382) — U.S. Internal Revenue Code Section 382, which limits a corporation's ability to use pre-acquisition net operating losses after a more-than-50% ownership change.
- Asset purchase — A deal structure in which the buyer acquires specific assets (and assumes specific liabilities) of the target, rather than buying its equity. Generally favoured by buyers for liability and tax reasons.
- Tax due diligence — The tax-focused workstream of buy-side diligence: federal/state/local income tax exposure, sales-and-use tax, payroll tax, transfer pricing, R&D credits, and the tax history of the target entity.