MLI
Multilateral Instrument
- What it is
- A multilateral convention that amends many tax treaties at once
- Why it was created
- To introduce measures against tax treaty abuse quickly
- The main mechanism
- The principal purpose test: benefits are denied if a transaction was designed mainly to obtain them
- What this means
- Formal compliance with a treaty is no longer enough
- The practical conclusion
- A structure must have a business purpose beyond the tax benefit
In plain words
The MLI is a multilateral convention that makes it possible to amend a large number of bilateral tax treaties at once. Without it, each treaty would have had to be renegotiated separately, which would have taken decades. On joining the convention, a country specifies which of its treaties are affected and which provisions it adopts.
The main practical innovation is the principal purpose test. In essence: if obtaining a benefit under a tax treaty was one of the principal purposes of a transaction or structure, and there is no business purpose behind it, the benefit may be denied. Formal compliance with the letter of the treaty is no longer sufficient.
For clients the conclusion is concrete. Schemes in which a company in a particular country was set up solely for a reduced withholding rate have become noticeably more vulnerable. A structure must have a clear business rationale: real activity, presence, economic sense beyond the tax saving. This is the substantive shift that the MLI has consolidated.
When it comes up
What the convention changes
- Amending many treaties at once
- Each country chooses the provisions
- Compatibility of the parties’ positions
- The principal purpose of the transaction
- Existence of a business purpose
- Denial of the benefit
- Genuine activity
- Staff and decisions
- Economic sense
- Withholding rates
- Double taxation
- Reviewing the structure
How to check your structure
- 01Identify the applicable treaties
- 02Check whether they are affected by the MLI
- 03Assess the structure’s business purpose
- 04Remove the weak points
- 05Document the rationale
What you need to know
- The convention amends many treaties at once
- Countries choose which provisions to adopt
- The principal purpose test is the key innovation
- Formal compliance with the treaty is not enough
- The structure’s business purpose must be documentable
Common mistakes
- Relying on the treaty text without taking the changes into account
- Building a structure solely for a preferential rate
- Having no documented rationale for the business purpose
- Using companies without real presence
- Relying on schemes that worked before these changes
What this means for a BRIDGES client
We review clients’ existing structures for their sustainability: is there a business purpose, is there presence, will the arrangement withstand scrutiny. Schemes from the last decade often need to be revisited.
Frequently asked questions
01 /What is the MLI?
A multilateral convention that makes it possible to amend many bilateral tax treaties at once and introduce measures against abuse.
02 /What is the principal purpose test?
A rule under which a benefit may be denied if obtaining it was one of the principal purposes of the transaction and there is no business purpose behind it.
03 /Is it enough to comply with the text of the treaty?
Not any more. Beyond formal compliance, the substance is assessed: does the structure have a real business purpose.
04 /Are all treaties affected?
No. Those that both parties have listed are affected, to the extent of the provisions adopted by both countries. This is checked for the particular pair of countries.
05 /What to do with the old structure?
Assess the business purpose and presence, remove the weak points and prepare a documented rationale — or simplify the structure.
06 /How can a business purpose be proved?
By real activity, staff, the place where decisions are taken, the economic sense of the transactions and documents confirming all of this.
See also
Read next


This material has undergone editorial review by BRIDGES.
Structure built a long time ago?
We will check how it stands up to current requirements — before the tax authority does.