→ Usman Qureshi — Audit & CFO Advisory

IAS 12 in M&A: Deferred Tax on Acquisition Fair Value Adjustments

By Usman Qureshi (ACCA, ACA) · Published July 2026 · 11 min read
In this guide

In business combinations, purchase price allocation (PPA) creates fair value step-ups on identifiable assets and liabilities. These step-ups are often not tax-deductible, creating deferred tax liabilities. This guide covers the mechanics, goodwill impact, and audit scrutiny around acquisition-related deferred tax.

Why Acquisition Deferred Tax Matters

In an acquisition, the buyer pays (say) £100m for assets with a book value of £60m. The £40m step-up is recognized at fair value (IFRS). But tax authorities often allow no tax deduction for the step-up (except depreciation on PP&E).

Result: Deferred tax liability is created on non-deductible step-ups, which reduces goodwill (or increases the "cost" of the acquisition).

Deductible vs Non-Deductible Step-Ups

Deductible (Create DTA, not DTL)

Non-Deductible (Create DTL)

Calculation of Acquisition DTL

Step 1: Identify Fair Value Adjustments

All amounts by which fair value exceeds tax base at acquisition date.

Step 2: Determine Tax Deductibility

Will this adjustment create a tax deduction? If no, a DTL applies.

Step 3: Apply Tax Rate

DTL = Non-Deductible Fair Value Adjustment × Tax Rate

Step 4: Offset Against Goodwill

The DTL reduces goodwill (or is recognized as a separate liability, depending on classification).

Worked Example: Acquisition with Deferred Tax Step-Up

Deal Overview

Buyer: GlobalCorp
Target: AcquireCo
Purchase price: £150m
Tax rate: 19%

Fair Value Adjustments (PPA)

Asset/Liability Book Value Fair Value Adjustment Tax Deductible?
Inventory 20 22 2 Yes (deducted cost of sales)
PP&E 40 55 15 Partial (depreciation deductible)
Intangible: Software 0 20 20 No (non-deductible)
Intangible: Customer List 0 15 15 No (non-deductible)
Provision: Warranty 0 (8) (8) Yes (deductible when paid)

Deferred Tax Impact

Non-Deductible Adjustments (Create DTL)

Deductible Adjustments (Create DTA)

PP&E Partial Deduction

Net Deferred Tax Position

PPA Goodwill Calculation (Impact of DTL)

Key point: The £8.13m DTL reduces the "net" identifiable assets, increasing goodwill. Higher goodwill = more impairment testing risk post-acquisition.

Future Reversal of Acquisition DTL

Depreciation Reversal

As PP&E is depreciated for tax purposes, the DTL reverses:

Impairment/Sale Reversal

If intangible assets (software, customer list) become impaired or are disposed:

Audit Red Flags: Acquisition DTL

Red Flag 1: DTL Not Recognized

Finding: PPA includes £30m of non-deductible intangibles, but no DTL recognized.

Auditor action: Calculate DTL (£30m × tax rate); recognize liability; reduce goodwill or increase P&L tax expense.

Red Flag 2: Incorrect Tax Deductibility Assessment

Finding: Customer list assumed non-deductible in the US (correct); but also treated as non-deductible in the UK (incorrect — UK allows amortization of intangibles acquired post-2002 as tax-deductible).

Auditor action: Reassess by jurisdiction; recognize DTA for UK amortization; reduce DTL.

Red Flag 3: DTL Not Remeasured for Rate Change

Finding: Tax rate changes post-acquisition; acquisition DTL not remeasured.

Auditor action: Remeasure DTL at new rate; adjust balance sheet and P&L (or goodwill if within measurement period).

Red Flag 4: Goodwill Calculation Omits DTL

Finding: Goodwill calculated as Consideration −’ Fair Value of Net Assets, with no DTL deduction.

Auditor action: Goodwill calculation must account for the DTL liability; reduce goodwill by DTL amount.

Real-Life Case Study: Deferred Tax on Acquired Intangibles

Scenario. In a business combination, an acquirer recognises a £8m customer-relationship intangible. For tax, no deduction is available (tax base nil). Tax rate 25%.

Treatment. A taxable temporary difference of £8m arises, so a £2m deferred tax liability is recognised at acquisition. Because it is recognised as part of the acquisition accounting, the offsetting entry increases goodwill, it does not go to P&L.

Takeaway. Fair-valuing intangibles in a PPA almost always drags a deferred tax liability with it, and that DTL grosses up goodwill. Omitting it understates both goodwill and liabilities on day one.

Illustrative composite scenario for educational purposes. Figures are indicative and do not represent any specific company.

Related Articles in This Cluster

→ IAS 12 Deferred Tax Hub

• IAS 12 Tax Loss Carryforwards: DTA Recognition & Utilization

• IAS 12 Valuation Allowances: DTA Realizability Assessment

• IAS 12 Tax Rate Changes: Remeasuring Deferred Tax Balances

• IAS 12 Deferred Tax on OCI: Recognizing Tax Effects in Other Comprehensive Income

Disclaimer: Acquisition deferred tax is complex and jurisdiction-specific. Tax deductibility of fair value adjustments varies significantly by country and asset type. Engage tax specialists early in the PPA process. DTL calculations are heavily audited and frequently adjusted.