Common Valuation Challenges in Purchase Price Allocation and How to Solve Them

Published on 17 Aug, 2026

The most consequential PPA challenges are not methodological. They arise from data gaps, structural complexity, and time pressure that emerge after the deal closes. Knowing what to anticipate and how to address each challenge makes the difference between a smooth engagement and a difficult audit.

Common Valuation Challenges in Purchase Price Allocation

I. Limited or Poor Quality Financial Data From the Target

The MPEEM — the standard methodology for valuing customer relationships — requires revenue attributable to existing customers, customer attrition rates, and margin data at the customer cohort level. Many acquired businesses, particularly founder-led companies and businesses being carved out of a larger group, have never compiled this data in the form the valuation requires. Revenue is tracked by product or geography rather than by customer cohort. Attrition is not formally measured. Margin at the customer level does not exist in the financial records.

The same problem applies to technology assets. The relief from royalty method requires revenue attributable specifically to the technology being valued. Where the acquired business has not separated technology revenue from service revenue in its reporting, that split must be estimated which introduces judgment and audit risk into what would otherwise be a straightforward calculation.

Impact if unaddressed: the valuation firm works with approximated inputs that carry higher uncertainty. Auditors challenge the basis for the approximation. The engagement extends as supplemental data is sought from target management post-close. In the worst case, the customer relationship or technology asset value is challenged and must be rebuilt from better data, extending the measurement period.

How to address it: request customer-level revenue and attrition data as part of financial due diligence, before close rather than after. Identify data gaps during the due diligence phase and agree a plan for how they will be addressed post-close. Where gaps cannot be filled from historical records, management interviews can provide the operational context needed to develop reasonable estimates but those estimates must be documented with clear rationale.

II. Contingent Consideration with Non-standard Milestone Structures

Earnouts tied to financial milestones — revenue targets, EBITDA thresholds — can be valued using Monte Carlo simulation or probability-weighted scenario models with inputs drawn from the management projections used to support the acquisition. The data requirements are demanding but manageable.

Non-standard milestones create a fundamentally different challenge. An earnout contingent on regulatory approval of a drug candidate, a successful product launch, or the outcome of a patent dispute has a payoff structure that cannot be derived from financial projections alone. The probability of success must be estimated from external data — clinical trial success rates, regulatory approval histories, litigation outcomes for comparable cases. That data exists but requires specialist knowledge to interpret and apply correctly.

The challenge compounds where a single transaction includes multiple earnout tranches with different milestone types — some financial, some regulatory, some operational. Each tranche requires its own modelling approach, and the interaction between tranches must be considered where achieving one milestone affects the probability of achieving another.

Impact if unaddressed: earnout valuations based on inappropriate models or unsupported probability assumptions are among the most frequently challenged items in PPA audit reviews. An incorrect acquisition-date earnout value also affects subsequent remeasurement, creating a compounding error across multiple reporting periods.

How to address it: identify all milestone structures in the acquisition agreement at engagement initiation and assess each one's modelling requirements before the valuation work begins. Where non-standard milestones require specialist input such as clinical stage probability data, regulatory approval rates, engage a sector specialist alongside the valuation firm. Document the probability assumption derivation with explicit reference to the external data sources used. For more on earnout valuation methodology, see Valuing Earnouts and Contingent Consideration in Business Combinations.

III. Cross-border acquisitions running under two standards simultaneously

A US acquirer purchasing a business with subsidiaries in multiple jurisdictions may need a PPA that satisfies ASC 805 for the consolidated US GAAP financial statements and IFRS 3 for the statutory accounts of individual subsidiaries. The intangible asset identification and valuation work is substantially the same under both standards. What differs is the NCI measurement, the goodwill calculation, and certain contingent consideration treatment — as set out in ASC 805 vs IFRS 3: How the Two Standards Define the Valuation Scope Differently.

Running both simultaneously creates three practical complications. First, the NCI election under IFRS 3 must be made before the valuation engagement is scoped — a decision that affects whether an independent NCI valuation is required and directly affects the goodwill figure under the IFRS 3 statutory accounts. Second, the timeline for statutory account preparation may differ from the measurement period timeline for the consolidated US GAAP statements, requiring the valuation firm to produce outputs in a different sequence than a domestic engagement. Third, the acquirer's auditors for the consolidated statements and the statutory auditors for individual subsidiaries may have different questions and documentation expectations.

Impact if unaddressed: the NCI election is made late — after the valuation scope is set — requiring rework. The IFRS 3 and ASC 805 goodwill figures are inconsistent in ways that cannot be explained by the NCI election alone, attracting questions from both sets of auditors. The timeline for statutory account delivery is missed because the PPA was scoped only for the consolidated timeline.

How to address it: confirm the applicable standards for each entity in the acquisition structure at engagement initiation. Make the IFRS 3 NCI election in consultation with the statutory auditors before scoping begins. Produce a single engagement timeline that accounts for both the consolidated and statutory reporting deadlines. Engage a valuation firm with documented experience in both ASC 805 and IFRS 3 engagements.

IV. Measurement Period Pressure and the Provisional Allocation Decision

Acquisitions that close late in a financial reporting period leave very little time between close and the first reporting date. Where the purchase price allocation cannot be completed before that date, a provisional allocation must be presented. The provisional allocation is not a placeholder, it must represent the best available estimate at the time and will be scrutinized by auditors in the same way as a final allocation. A provisional allocation that is clearly inadequate will not satisfy the measurement period framework.

The pressure is compounded where the acquiring company is itself publicly listed and subject to SEC filing deadlines. The SEC requires business combination financial information to be filed within 75 days of the acquisition date for significant acquisitions. The PPA does not need to be final within that window, but the financial statements accompanying the filing must include a provisional allocation that is defensible.

The most common cause of inadequate provisional allocations is late engagement of the valuation firm. Where the valuation firm is engaged after the first reporting date has passed, there is no opportunity to produce even a provisional allocation in time. The acquirer is then in the position of presenting financial statements with no allocation at all, which is neither permitted under ASC 805 nor defensible in an audit.

Impact if unaddressed: an inadequate provisional allocation delays audit sign-off, triggers SEC comment letters for public companies, and requires retrospective adjustment of previously filed financial statements when the final allocation is completed. Each of these outcomes is significantly more disruptive and costly than initiating the PPA engagement promptly after close.

How to address it: engage the valuation firm within two weeks of close, not at the first audit fieldwork date. For acquisitions that close late in a reporting period, discuss the provisional allocation approach with the valuation firm at engagement initiation so that a defensible provisional figure can be produced quickly, even where the full analysis is not yet complete. For more on the measurement period and provisional allocations, see Step-by-Step Process of Purchase Price Allocation in M&A Transactions.

How to Get Ahead of These Challenges Before Close

Every challenge described above is significantly easier to manage when it is identified before the acquisition closes rather than after. The following steps taken during the due diligence and pre-close phase reduce the risk of each challenge materializing in the post-close PPA engagement.

1. Identify the intangible asset profile of the target during due diligence

Understanding which intangible assets are likely to be significant and what data will be needed to value them allows the acquirer to request that data as part of financial due diligence rather than as a supplemental request post-close. Customer cohort data, technology revenue attribution, and brand royalty comparables are all more accessible before close than after.

2. Review all earnout structures in the acquisition agreement before signing

Every milestone type in the earnout should be reviewed for its modelling requirements before the agreement is executed. Where non-standard milestones require specialist probability data, that data source should be identified before close so it is available when the valuation begins.

3. Confirm the applicable accounting standards for every entity in the acquisition structure

For cross-border transactions, map each acquired entity to its applicable standard and make the IFRS 3 NCI election before the valuation engagement is scoped. This takes one conversation with the statutory auditors but prevents significant rework later.

4. Engage the valuation firm before close where the timeline allows

A valuation firm engaged before close can review the acquisition agreement, identify data requirements, and begin document collection on day one post-close. This can reduce the time from close to first draft report by several weeks which is material where reporting deadlines are tight.

The common thread across all four challenges is timing. Data gaps, earnout complexity, cross-border structure, and measurement period pressure are all more manageable when they are identified early. The acquirer that treats the PPA as a post-close compliance exercise will encounter each of these challenges at the worst possible time. The acquirer that plans for the PPA as part of the deal process will encounter most of them before they become problems.

Key Takeaways

Limited financial data from the target is the most common cause of PPA delay. Customer-level revenue, attrition data, and technology revenue attribution should be requested during financial due diligence, before close
Non-standard earnout milestones such as regulatory approvals, clinical outcomes, patent disputes, require probability inputs that cannot be derived from management projections alone. Specialist external data sources must be identified and engaged before valuation modelling begins
Cross-border acquisitions requiring both ASC 805 and IFRS 3 PPAs must resolve the IFRS 3 NCI election before the valuation engagement is scoped. A late election requires rework and creates inconsistency between the consolidated and statutory goodwill figures
Measurement period pressure is most acute for acquisitions closing late in a reporting period. Engaging the valuation firm within two weeks of close is best practice. A provisional allocation that cannot be defended is no better than no allocation at all
Every challenge is easier to manage before close than after. Treating the PPA as part of the deal process rather than as a post-close compliance exercise is the single most effective mitigation across all four challenges