This Practice Note looks at the UK’s transfer pricing legislation applicable to loans, guarantees and other financing arrangements as it applied prior to the reforms introduced by Finance Act 2026—ie it covers the rules generally applicable to accounting periods beginning before 1 January 2026, although note that the Finance Act 2026 commencement provisions contain certain transitional rules for existing loans. For the post-Finance Act 2026 rules and more information on the commencement provisions, see Practice Note: Transfer pricing—loans and guarantees (post 1 January 2026). As more fully discussed in Practice Note: Transfer pricing—key concepts and principles, ‘transfer pricing’ refers to the pricing of goods, services, funds, and tangible/intangible assets provided between connected parties—broadly, companies who are affiliated in some way (note that the participation condition is the relevant test of connection in the UK’s transfer pricing rules). Due to the connection between the parties, transactions between them (often known as ‘controlled’ transactions) may not be subject to normal market pressures which establish prices for similar transactions