Valuations under HMRC scrutiny: Evidence that matters
Why valuations are under increasing HMRC scrutiny
When HMRC challenges a valuation, the focus is rarely on whether a particular multiple or discount rate is “right” or “wrong” in isolation. Instead, scrutiny increasingly focuses on whether assumptions are robust, defensible, and grounded in commercial reality.
More often, HMRC scrutiny centres on whether the valuation assumptions are properly supported, internally consistent, and clearly documented. As HMRC enquiries become more detailed and technically informed, the quality, structure and clarity of valuation reporting is now as important as the valuation itself.
This is particularly relevant for businesses undertaking transactions, restructuring or tax planning, where valuations must withstand formal review.
In practice, many valuations encounter difficulty not because the methodology is flawed, but because the supporting narrative was prepared to justify an outcome, rather than to withstand independent review.
As HMRC enquiries become increasingly detailed and technically informed, the quality and clarity of valuation reporting have become as important as the valuation itself.
This article explores the areas of analysis that most often come under HMRC scrutiny, and where, in our experience, valuations most commonly fall short.
What HMRC typically reviews first
It is our understanding that HMRC rarely begins by rebuilding a valuation model from scratch. Instead, initial attention is usually directed towards:
- The commercial rationale for the valuation;
- The consistency between the valuation narrative and the wider transaction or tax planning;
- Whether key assumptions have been clearly articulated and evidenced; and
- The extent to which downside risks have been acknowledged.
Valuations that appear one‑sided or outcome‑driven can attract greater, rather than less, scrutiny. In practice, HMRC expects valuation assumptions to be capable of challenge and testing and to give a fair and balanced view of the business or asset being valued.
Supporting evidence that carries the most weight
1. Commercial rationale and context
HMRC needs to understand why a valuation is required and how it fits within the broader commercial and tax context.
- Effective reporting explains:
- The purpose of the valuation;
- The nature of the interest being valued; and
- How the valuation aligns with the underlying transaction or structure.
HMRC guidance, including the SAV manual, emphasises the importance of clearly explaining the context and evidential basis for a valuation. Where this context is missing or unclear, this can lead HMRC to question whether the valuation appropriately reflects commercial reality or has been unduly influenced by the tax position.
2. Basis of valuation
HMRC generally expects valuations to be prepared on a “market value” basis, unless specific legislation states otherwise.
“The price that the asset might reasonably be expected to fetch if sold in the open market at that time.”
This is set out in Section 272 of the Taxation of Chargeable Gains Act 1992 (TCGA 1992).
Other key aspects of HMRC’s market value basis that must be taken into consideration are the following:
- Hypothetical sale: The valuation assumes a theoretical sale at the valuation date.
- Willing buyer and willing seller: Both parties are motivated but under no pressure to transact.
- Arm’s length transaction: The parties act independently, without any special relationship influencing the price.
- Proper marketing: The asset is assumed to have been adequately exposed to the open market to achieve the best price reasonably obtainable.
- No compulsion: Neither buyer nor seller is forced to enter into the transaction.
- Knowledgeable parties: Both parties are reasonably informed about the asset and market conditions and act prudently.
3. Forecasts and underlying assumptions
We understand that HMRC conducts a rigorous analysis of valuations. Given the significant influence forecasts have on valuation outcomes, they will typically be a key area of HMRC scrutiny.
A valuation report should cover the following in respect of prospective financial information:
- Who prepared the forecasts?
- When were they prepared?
- Were they used for any other commercial purpose?
- How do they compare to historical performance?
Clear evidence of management involvement, key assumptions, and known risks significantly improves credibility. Forecasts that appear detached from past performance or wider business planning often attract challenge.
4. Methodology selection and application
HMRC does not have its own valuation methods – those commonly applied, such as cost, income and market approaches are all acceptable. Each needs to be supported by:
- A clear explanation of why a particular method was appropriate;
- Consideration of alternative approaches, even if ultimately rejected; and
- Evidence that the method was applied consistently with the valuation’s purpose.
A lack of explanation around methodology might suggest that the most advantageous method for the client has been used.
5. Market evidence and comparables
Market data is most persuasive when it is relevant, reliable, and clearly applied as an input to recognised valuation methods (e.g. market multiples or transaction benchmarks), with appropriate consideration of comparability, timing, and the specific characteristics of the underlying asset:
- Relevant to the company’s size, sector, and stage of development;
- Clearly sourced and explained; and
- Used thoughtfully rather than mechanically.
Generic or poorly aligned comparables can weaken an otherwise robust valuation.
6. Consideration of downside risk
While formal sensitivity analysis or multiple scenarios are not always warranted, HMRC’s focus is typically on whether downside risks have been appropriately reflected within the core assumptions, and whether those assumptions are robust, clearly supported, and commercially realistic.
In practice, this may involve considering:
- Whether the selected assumptions reflect the most reasonable and supportable view of future performance;
- The extent to which risks and uncertainties have been identified and factored into those assumptions; and
- Whether the overall conclusion remains commercially coherent in the context of the business and transaction.
Where uncertainty is not addressed in a proportionate way, HMRC is more likely to test the underlying assumptions and supporting evidence in detail.
Where valuations commonly fall short
In our experience, HMRC challenges frequently arise due to:
- Boilerplate wording reused across different valuations;
- Assumptions that contradict transaction pricing or investor behaviour;
- Inadequate explanation of judgement heavy inputs; and
- Insufficient audit trail of discussions with management.
These issues are typically avoidable with early consideration of how the valuation might be reviewed by an external party.
Practical considerations
Preparing valuation documentation with HMRC scrutiny in mind often involves:
- Involving valuation specialists early in the process;
- Aligning valuation, tax and legal advice; and
- Documenting judgement, not just calculations.
Early focus on documentation can reduce both the duration and intensity of HMRC enquiries.
Key takeaway for businesses
Valuations rarely fail because of a single number. They fail when the story behind the numbers does not stand up to independent scrutiny.
