Plain English
Instead of a parent lending directly to a subsidiary, money sometimes flows through an intermediate finance company: the finance company borrows externally or from one group entity, then re-lends to the ultimate borrower, keeping a small margin for itself. Done for genuine treasury centralisation reasons this is normal; done purely to route interest through a low-tax jurisdiction with an intermediary that adds no real function, it is a classic audit target.
Technical definition
A back-to-back loan structure involves an intermediary entity that borrows funds (externally or intra-group) and on-lends them on matching or near-matching terms to another group entity, requiring accurate delineation under OECD Chapter X to determine whether the intermediary performs genuine treasury functions warranting a spread, or is a conduit with no substantive role, in which case its margin may be denied recognition.
Why it matters
Tax authorities routinely challenge back-to-back structures where the intermediary lacks the people, systems and risk-bearing capacity to justify its margin, treating it instead as a pass-through with the spread reallocated to the entities actually performing the treasury function.
How it works in practice
- 01Confirm the intermediary has genuine substance: staff, decision-making authority, and risk management capability.
- 02Delineate whether the intermediary actually assumes and manages the credit and interest rate risk, or merely passes it through.
- 03Price the inbound and outbound legs of the loan independently against market comparables.
- 04Determine an arm's length spread for the intermediary's genuine treasury function, if any.
- 05Document the substance analysis alongside the pricing of both legs.
Worked example
A finance company with genuine treasury substance
A regional finance company borrows USD 30m externally at 5.2% and on-lends USD 30m to an operating subsidiary at 6.0%, an 80bps spread. The finance company employs a three-person treasury team that manages currency and interest rate risk, sets internal credit policy, and has capital at risk beyond the loan amounts. Comparable third-party treasury centres earn spreads of 60–100bps for similar functions, supporting the 80bps as arm's length. Had the entity had no staff and simply passed funds through unchanged, the spread would likely be denied entirely.
Common mistakes
- Locating the intermediary purely for tax reasons with no operational treasury team.
- Pricing both legs identically (zero spread) while still claiming a treasury function exists.
- Failing to document the intermediary's actual risk management activity, not just its contractual role.
Audit red flags
- Intermediary with no employees or decision-making capability.
- Matching terms on both legs down to the basis point, suggesting no genuine risk assumption.
- Intermediary located in a jurisdiction with no connection to the group's real treasury operations.
Documentation & data
Documents to hold
- Functional analysis of the intermediary's treasury activities.
- Pricing analysis for both the inbound and outbound legs.
- Evidence of staffing, systems and decision-making at the intermediary.
Data you need
- Terms of both loan legs.
- Intermediary's headcount, systems and governance documentation.
- Comparable treasury centre margin data.
Who owns this internally: Group treasury operates the structure; tax defends substance and pricing jointly with treaty specialists.
Jurisdiction notes
- OECD
- Chapter I delineation principles, reinforced by Chapter X, govern whether an intermediary's margin is recognised.
- European Union
- Anti-conduit and principal purpose test provisions under ATAD and MLI can deny treaty benefits on back-to-back structures lacking substance, independent of transfer pricing.
Notes by role
Advisors & consultants
Substance documentation for the intermediary is usually more decisive than the pricing analysis itself in these audits.
In-house tax teams
Coordinate transfer pricing substance analysis with the treaty/anti-conduit team early — the two reviews often overlap.
Frequently asked
- Is a zero-substance conduit ever acceptable?
- No under current OECD and most domestic standards — a margin without a corresponding function is not defensible.
- Does this overlap with anti-conduit treaty rules?
- Yes, substance concerns are tested both under transfer pricing delineation and separately under treaty anti-abuse provisions.
Sources & status
- Primary source
OECD Transfer Pricing Guidelines, Chapter I, Section D.1 and Chapter X
OECD, 2022
Reference material only, not advice on a specific fact pattern. Reviewed 2026-06-30.
Careers
How this shows up in the job
Back-to-back structures are a common M&A and treasury-restructuring interview topic — know both the transfer pricing and treaty-substance angles.
Careers in transfer pricing