What it calculates

Transfer pricing tests whether the price charged between related entities matches what unrelated parties would have agreed - the arm's-length principle. It determines how a multinational's profit is divided between jurisdictions, and it is the single largest source of cross-border tax disputes.

How it is calculated

Select a tested party and a profit level indicator, typically operating margin, net cost plus, or return on assets. Assemble a set of independent comparables performing similar functions with similar risks, and compute their results across several years. The interquartile range of those results is the arm's-length range. If the tested party's result falls inside it, no adjustment is required. If it falls outside, an adjustment is made, generally to the median rather than to the nearest edge.

How to read the result

The width of the range is a measure of comparable quality: a wide range usually means the comparable set is loose and will not withstand challenge. Position within the range matters too - sitting at the very edge invites scrutiny even where technically compliant. Test annually and keep contemporaneous documentation, because most penalty regimes are documentation-based, and a defensible file assembled at the time is worth more than a better analysis produced years later under audit.

Worked example

Eight comparables show operating margins from 2.1% to 9.4%, with a first quartile of 3.6%, a median of 5.2% and a third quartile of 7.1%. The arm's-length range is 3.6% to 7.1%. A tested party at 2.4% is below the range, so an adjustment to the 5.2% median is proposed.

Common questions

Which method should be used?

The most appropriate to the facts. Comparable uncontrolled price is the most direct where a genuinely comparable third-party transaction exists. In practice the transactional net margin method dominates, because reliable margin data on comparable companies is far easier to find than comparable transaction prices.

Why adjust to the median rather than to the nearest quartile?

Most tax authorities take the position that a result outside the range indicates the pricing is unreliable, not merely marginal, so the whole distribution should be used as the best estimate. Adjusting to the nearest edge would let a taxpayer sit permanently at the boundary.

What is an advance pricing agreement?

A negotiated agreement with one or more tax authorities fixing the transfer pricing methodology in advance for a set period. It is slow and costly to obtain but removes audit risk and, where bilateral, protects against the same profit being taxed in two countries.