Published October 15, 2023Updated August 16, 202618 min read
TNMM in Transfer Pricing: Tested Party, PLI & Worked Example (2026)TNMM in Transfer Pricing: Tested Party, PLI & Worked Example (2026)
A practical guide to the Transactional Net Margin Method: when TNMM fits, tested-party and PLI selection, segmentation, comparables, a checked numerical example, and the distinction from US CPM.
Borys UlanenkoCEO of ArmsLength AI
18min read
Contents↓
Contents
TL;DR key takeaways
TNMM examines the net profit from a controlled transaction relative to an appropriate base such as costs, sales, or assets.
Select TNMM only after comparing it with more direct methods; the absence of unique contributions does not automatically make TNMM the most appropriate method.
The tested party is the party to which the method can be applied most reliably and for which reliable comparables can be found, often the less complex party.
PLI selection, transaction-level segmentation, accounting consistency, comparable-company screening, and justified adjustments determine whether the result is reliable.
US CPM and OECD TNMM use closely analogous one-sided net-profit mechanics, but their legal authority, terminology, range rules, and procedural application must be documented separately.
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The Transactional Net Margin Method (TNMM) examines the net profit that a taxpayer earns from a controlled transaction, or an appropriate aggregation of transactions, relative to a base such as costs, sales, or assets. The resulting ratio is compared with reliable uncontrolled evidence.
TNMM is a one-sided method: it tests a financial indicator for one party, called the tested party. That does not mean the other party can be ignored. The functional analysis must cover both sides before the transaction, tested party, method, and profit level indicator can be selected.
Note
defines TNMM and states that internal comparable net-profit indicators should ideally be considered before external comparables. Where external comparables are used, a functional and comparability analysis is still required.
the accurately delineated transaction can be tested using a net-profit indicator;
one party can be tested more reliably than the other;
reliable internal or external comparable data exist;
the tested transaction can be segmented in the accounts; and
material differences in functions, assets, risks, accounting, or economic circumstances can be eliminated or adjusted reliably.
It often becomes practical when direct price or gross-margin evidence is unavailable or less reliable. That is not a shortcut around method selection. OECD paragraphs 2.1-2.12 require the method most appropriate to the circumstances. Where a traditional transaction method and a transactional profit method can be applied with equal reliability, the traditional transaction method is preferred; where CUP and another method are equally reliable, CUP is preferred.
Amount B checkpoint for baseline distribution
Before starting an ordinary TNMM company search for a baseline marketing and distribution transaction, check whether Amount B applies in the relevant jurisdiction and period. The OECD incorporated the simplified and streamlined approach into the Guidelines in 2024 and published a consolidated report in 2025, but domestic implementation, options, scope and exclusions remain jurisdiction-specific. If Amount B does not govern the transaction, the usual most-appropriate-method analysis and local rules continue to apply.
When TNMM is unlikely to be reliable
TNMM needs particular scrutiny when:
both parties make unique and valuable contributions;
operations are so integrated that neither party can be tested reliably on its own;
the tested party owns or develops unique intangibles relevant to the transaction;
the available accounts cannot isolate the controlled activity;
the proposed comparables contain material functional or accounting differences that cannot be adjusted reliably; or
a reliable internal CUP or other direct method is available.
OECD paragraph 2.65 says TNMM is unlikely to be reliable where each party makes unique and valuable contributions. A profit split method may then be more appropriate. Paragraph 2.67 also makes the reverse point: a lack of unique contributions does not automatically make TNMM the right method.
2. Delineate the transaction before choosing the tested party
Start with the parties' actual conduct, not the return stated in the policy. Describe:
the products, services, financing, or rights transferred;
contractual terms and the conduct that implements or differs from them;
functions performed by each party;
assets used, including relevant intangibles;
economically significant risks, who controls them, and who has the financial capacity to assume them;
economic circumstances and business strategies; and
how the controlled transaction appears in each party's accounts.
Do not group transactions merely because they involve the same legal entities. OECD paragraphs 3.9-3.12 permit aggregation when transactions are so closely linked or continuous that they cannot be evaluated adequately on a separate basis.
The output of this step should be a transaction map and a financial-data map. Both are needed before selecting the tested party.
3. Select the tested party
Under , the tested party is generally the party to which the method can be applied most reliably and for which the most reliable comparables can be found. It will often be the party with the less complex functional analysis.
Tested-party decision sequence
Compare the functions, assets, and risks of both parties.
Identify any unique and valuable contributions on either side.
Determine which party's controlled activity can be segmented reliably.
Assess the availability and quality of internal and external comparables for each possible party.
Test whether material differences can be adjusted consistently.
Select the party that produces the more reliable application, and record why the other party was not selected.
Candidate fact
Effect on tested-party reliability
Performs defined support or routine operating functions
May support selection if the functions and data are genuinely comparable
Owns or develops unique intangibles used in the transaction
Usually weighs against one-sided testing of that party
Controls strategic market, product, or technology risks
May make the party too complex for a reliable external comparison
Has clean segmented accounts for the controlled activity
Improves reliability
Operates several inseparable controlled and uncontrolled businesses
Reduces reliability unless appropriate aggregation or segmentation is possible
Has strong internal comparable transactions
May support testing that party and may support a more direct method
Warning
"Limited-risk" is a conclusion from the functional and risk-control analysis, not a substitute for it. A contractual label or target margin cannot prove which party should be tested.
4. Choose a profit level indicator
OECD paragraph 2.82 says the PLI should reflect the transaction and functional analysis, the strengths and weaknesses of the indicator, the available reliable information, comparability, and the reliability of adjustments.
PLI
Formula
Possible fit
Main checks
Operating margin
Operating profit / sales
Sales are a relevant base for the tested functions, often in distribution
Revenue recognition, rebates, freight, and operating-expense consistency
Net cost plus
Operating profit / relevant operating costs
Costs have a reliable relationship to the tested activity, often in services or manufacturing
Cost-base definition, allocation keys, pass-through costs, and consistent comparable treatment
Return on operating assets
Operating profit / relevant operating assets
Operating assets are an important value driver
Asset classification, leases, depreciation, idle assets, and valuation consistency
Berry ratio
Gross profit / operating expenses
Limited intermediary facts meet the conditions in OECD paragraphs 2.106-2.108
Cost classification, pass-through items, and whether functions are unrelated to product value
Denominator discipline
OECD paragraphs 2.93-2.94 say the denominator should focus on the relevant indicators of value for the transaction and be reasonably independent from controlled pricing. The practical questions are:
Does the denominator measure the resources used in the tested activity?
Can it be calculated the same way for the tested party and comparables?
Can controlled charges distort it?
Does a change in the denominator represent a change in the value of the tested functions?
Pass-through costs
Do not remove a cost from the markup base because it came from a third party or is labelled "pass-through." OECD paragraphs 2.99-2.100 require a comparability and functional analysis of whether an independent party would earn a markup on that cost. If a cost is excluded from the tested party's denominator, it must also be treated consistently in the comparable PLI.
5. Build transaction-level financials
OECD paragraphs 2.83-2.85 require the net-profit calculation to include operating items related directly or indirectly to the tested transaction and to exclude unrelated items where they materially affect comparability. Company-wide TNMM is unreliable when the company conducts different activities that cannot be aggregated appropriately.
Financial bridge
Build a schedule from the approved accounts to the tested result:
Step
Evidence
Start with approved statutory or management accounts
Signed financial statements or controlled trial balance
Map transaction revenue
Counterparty, agreement, invoice, and account mapping
Map direct costs
Ledger accounts and cost centres
Allocate shared operating costs
Documented allocation keys and source data
Classify operating and non-operating items
Written accounting policy applied to tested party and comparables
Review exceptional and non-recurring items
Facts, risk allocation, and consistent comparable treatment
Treat foreign-exchange items
Analysis of whether they relate to the trading transaction and which party bears the risk
Calculate the PLI
Locked formula with unit, sign, and rounding controls
Reconcile back to the accounts
Bridge with explained differences and reviewer approval
Measurement consistency matters. Depreciation, provisions, stock compensation, leases, inventory, foreign exchange, and other items can move operating profit or the denominator even when the underlying functions are similar.
6. Identify and screen comparables
Check for internal comparable transactions before starting an external search. If external company data are needed, use a reproducible workflow:
define the functional profile and observable screening criteria;
choose a database whose coverage and fields fit the PLI;
record the search version, date, criteria, sequence, and population counts;
apply documented independence and financial-data screens;
review annual reports, websites, registries, and other public evidence manually;
record a company-specific reason for every acceptance and rejection;
map financial fields to a consistent PLI; and
apply comparability adjustments only when they improve reliability and can be calculated with reasonable accuracy.
OECD paragraphs 3.75-3.79 say multiple-year data may help explain cycles, losses, and anomalies but are not a systematic requirement. The OECD does not prescribe a fixed number of years and does not require an average simply because several years are reviewed.
State which years are used, why they add value, how averages are calculated, and whether the tested party and comparables use consistent periods.
7. Worked TNMM example
This example is illustrative. All amounts are in EUR millions.
Facts and method decision
A regional shared-services company provides routine accounting support to associated group entities. The functional analysis concludes that it uses group systems under direction, does not own unique intangibles, and does not control strategic business risks. Its controlled-service activity can be isolated in the accounts.
No reliable internal comparable service arrangement is available. After considering the practical alternatives, TNMM is selected with the service company as the tested party and net cost plus as the PLI. A documented external search produces an illustrative arm's length range of 4.0% to 7.0%, with a median of 6.0%.
This arithmetic is correct, but it does not decide whether a year-end adjustment should be made. Before changing an invoice or tax return, confirm:
whether 9.200 is the correct relevant cost base;
whether any pass-through costs need different treatment;
whether the range and point-selection rule are valid under the applicable law;
whether the contract permits a true-up;
which counterparty and transaction should bear the adjustment;
indirect-tax, customs, withholding-tax, and accounting effects; and
corresponding treatment in the other jurisdiction.
Note
An arm's length range is not a mechanical target. The method, range, point selection, and any adjustment must follow the facts and the applicable law.
8. TNMM versus US CPM
The OECD TNMM and the US Comparable Profits Method (CPM) are closely analogous one-sided net-profit methods. Both compare a tested party's profitability with uncontrolled evidence using a profit-based indicator. That conceptual overlap does not make the legal analyses interchangeable.
Issue
OECD TNMM
US CPM
Legal source
OECD Transfer Pricing Guidelines, principally Chapters II and III, as implemented under local law
US Treasury Regulations §1.482-5, together with §1.482-1 and related rules
Core measure
Net profit from the controlled transaction relative to an appropriate base
Operating profit of the tested party measured through a profit level indicator against uncontrolled taxpayers
Tested party
Party to which the method can be applied most reliably and for which reliable comparables can be found, often the less complex party
Participant whose operating profit attributable to the controlled transactions can be verified using the most reliable data and requiring the fewest, most reliable adjustments
Indicator vocabulary
Net profit indicator, such as profit relative to costs, sales, or assets
Profit level indicator specified under the US regulations
Range and adjustment
OECD arm's length range guidance plus domestic implementation
US arm's length range and adjustment rules under the Treasury Regulations
Documentation
OECD/local documentation framework
US contemporaneous-documentation and procedural rules where applicable
The workpapers may share financial calculations and comparable evidence, but the report should cite the correct authority and test the result under the applicable legal framework. Avoid saying that one label can simply replace the other.
9. Common TNMM failure modes
Failure
Why it weakens the analysis
Better control
Method selected because comparable-company data are easy to obtain
Data availability alone does not make TNMM the most appropriate method
Compare practical methods after delineating the transaction
Tested party selected from the policy label
"Routine" or "limited-risk" may not match actual conduct
Review both parties' functions, assets, risk control, and intangibles
Company-wide result used for mixed activities
Unrelated or different controlled activities distort the tested margin
Build transaction-level segmentation and a financial bridge
PLI chosen from an industry habit
The denominator may not reflect the tested activity
Link the PLI to the functional analysis and reliable comparable data
Pass-through costs removed by label
The tested and comparable denominators become inconsistent
Analyze whether independent parties would earn a markup and treat both sides consistently
Database codes treated as proof
Product, function, risk, or intangible differences remain hidden
Perform and document manual screening
Loss-makers automatically rejected
The set is biased without a comparability reason
Investigate losses under OECD paragraphs 3.64-3.65
Every outlier removed
Results are filtered to fit the tested outcome
Exclude only for a documented comparability defect
Fixed three-year average applied by habit
Multiple-year analysis may obscure the tested facts
State why the period and averaging method improve reliability
Range treated as a target
The analysis skips local point-selection and adjustment rules
Separate range testing from pricing and tax-adjustment decisions
10. TNMM reviewer checklist
TNMM application checklist
01The controlled transaction is accurately delineated and the aggregation decision is documented
02The practical reliability of TNMM is compared with CUP, gross-margin, and profit-split alternatives
03Both parties' functions, assets, risk control, and valuable contributions are analyzed before selecting the tested party
04The selected PLI has an economic relationship to the tested activity and can be calculated consistently
05Transaction-level financials reconcile to approved accounts with documented allocations and classifications
06Internal comparables were considered before an external company search
07The external search, manual screening, accepted set, and adjustments are reproducible
08Multiple-year data, averaging, range construction, and point selection each have a stated reason
09The worked result has been recalculated independently and does not rely on a spreadsheet output alone
10OECD TNMM and US CPM conclusions cite and apply their respective legal frameworks
TNMM stands for Transactional Net Margin Method. It examines net profit from a controlled transaction relative to an appropriate base such as costs, sales, or assets.
Is TNMM the same as CPM?
They are closely analogous in mechanics, but they are not the same legal rule. TNMM is described in the OECD Guidelines and takes legal effect under the relevant domestic law; CPM is defined in US Treasury Regulation §1.482-5. Use the correct authority, range rules, terminology, and documentation standard for each jurisdiction.
Which entity should be the tested party?
Choose the party to which the method can be applied most reliably and for which the most reliable comparables can be found. It is often the less complex party, but that conclusion must follow the functional analysis and data review.
Which PLI should a distributor use?
There is no automatic distributor PLI. Operating margin may fit when sales are an appropriate base. Return on assets may be relevant where operating assets drive value. A Berry ratio has narrower conditions and is not a generic distributor alternative. Test the indicator against the specific functions and comparable data.
Does TNMM require an interquartile range?
Not in every OECD case. Statistical tools such as the interquartile range may improve reliability when a sizeable set still contains unidentified or unquantified comparability defects. Domestic law may prescribe a particular convention.
Can TNMM use company-wide accounts?
Only when the company-wide activity corresponds reliably to the controlled transaction or transactions that are appropriately aggregated. If the entity has materially different businesses or uncontrolled activities, build transaction-level segmentation.
How many comparables are required?
The OECD Guidelines do not prescribe a minimum. A smaller set of reliable comparables can be stronger than a large, weak set. Document the search, evidence, and limitations rather than targeting a number.
How should losses be treated?
Investigate them. OECD paragraphs 3.64-3.65 say loss-making comparables should not be rejected solely because they have losses. Exclude them when their losses reflect non-comparable risks or abnormal conditions.
Can TNMM test a company with valuable intangibles?
It depends on the transaction, but unique and valuable contributions usually make a one-sided external comparison less reliable. If both parties make such contributions, profit split may be more appropriate.
Borys UlanenkoCEO of ArmsLength AI
