Part 4 of the Taxation (International and Other Provisions) Act 2010 (TIOPA 2010) requires UK companies to price transactions with connected persons — including subsidiaries, parent companies and sister entities — at the amount that would have been agreed between independent parties dealing at arm's length. The rule applies where the transaction has the potential to provide a UK tax advantage, regardless of whether the counterparty is UK-resident. HMRC explicitly adopts the OECD Transfer Pricing Guidelines (2022 edition) as the interpretive framework for all transfer pricing enquiries. Self-assessment requires taxpayers to substitute arm's length figures in their corporation tax return when non-arm's-length pricing results in excess deductions or understated UK profits.
The OECD provides five principal pricing methods: Comparable Uncontrolled Price (CUP), Resale Price Method (RPM), Cost Plus Method, Transactional Net Margin Method (TNMM) and Profit Split. CUP is considered the most direct method because it compares the actual transaction price to a price for an identical or closely comparable transaction between independents, but suitable comparables are rarely available for intangible-heavy businesses. TNMM — which benchmarks the taxpayer's net profit margin against margins earned by comparable independent companies — is the most commonly applied method by HMRC and taxpayers alike, partly because it is robust to minor product differences.
Aldbourne's UK parent licenses its proprietary analytics software to a Dutch subsidiary for an annual royalty of £500,000 on £12m of the subsidiary's EU revenue — an effective royalty rate of 4.2%. A TNMM benchmarking study identifies arm's length royalty rates of 6%–9% for comparable software transactions in the ORBIS database. At the 6% floor, the arm's length royalty is £720,000; Aldbourne's UK tax return must include the £220,000 adjustment to substitute the arm's length rate, increasing UK taxable income accordingly.
⚠️Assuming intra-UK group transactions are outside transfer pricing rules
→ TIOPA 2010 s.147 can apply to transactions between two UK group members where one entity benefits from a tax attribute (e.g. losses, patent box, R&D credits) that creates a UK tax advantage — domestic transactions are not automatically exempt.
⚠️Selecting a pricing method without first performing a functional analysis
→ The most appropriate OECD method depends on the functions performed, assets used and risks assumed by each party; applying TNMM without a comparability analysis that isolates the tested party's routine functions risks an HMRC challenge.
⚠️Using arm's length pricing to justify an artificially low management fee
→ Management charges must reflect actual services rendered; HMRC's International Manual (INTM413000) requires contemporaneous evidence that the service was genuinely provided and that the fee equals the cost plus an arm's length markup.