Tax Administrations Are Now Talking to Each Other

Türkiye Joins the GIR MCAA Information Exchange Network

1. The Big Picture: What Has Changed?

Presidential Decree No. 11396, published in the Official Gazette on 6 June 2026, marks Türkiye’s formal approval of the Multilateral Competent Authority Agreement on the Exchange of GloBE Information (GIR MCAA). The Agreement provides concrete evidence that the global minimum taxation architecture, Pillar Two, has evolved from a framework that exists on paper into a mechanism supported by real-time information flows between tax administrations.

This step carries strategic significance well beyond a technical multilateral instrument: Türkiye will no longer limit oversight of sensitive tax data on MNEs to domestic controls alone but will automatically exchange such information with the competent authorities of jurisdictions with which it has an active exchange relationship under the Agreement.

2. What This Agreement Is, and Is Not

The GIR MCAA governs the automatic exchange, between the tax administrations of signatory jurisdictions, of the information contained in the GloBE Information Return (GIR) that multinational enterprises (MNEs) are required to file annually. It does not create a new obligation; rather, it operationalizes the information infrastructure supporting the existing GloBE (Global Anti-Base Erosion Rules) / QDMTT (Qualified Domestic Minimum Top-up Tax) system.

The exchange is two-directional: Türkiye will share data received from constituent entities of MNEs established in its territory with the relevant jurisdictions, while also receiving from other jurisdictions data relevant to Türkiye. Which data goes to whom is determined by the “Dissemination Approach”: each jurisdiction accesses only the sections relevant to its own taxing rights.

Mechanism at a Glance

3. Entry into Force: A Three-Layer Structure

The approval of the Agreement does not mean that information exchange has actually begun. For any two jurisdictions to reach “Agreement in effect” status under Section 1(k), two additional steps are required beyond signature and approval: both jurisdictions must separately notify the OECD Co-ordinating Body Secretariat, listing each other under their respective send and receive preferences under Section 8. Until these bilateral notifications are completed, no active exchange relationship exists.

The current picture for Türkiye is as follows:

This table has a critical practical implication for MNEs: because no active exchange relationship has yet been established for Türkiye, constituent entities located in Türkiye cannot benefit from the centralized filing relief for the 2024 reporting fiscal year. Local filing obligations remain in force in the interim.

However, under the “temporary penalty relief” approach agreed between the OECD and signatory jurisdictions, no penalties will be imposed for failure to file a local return for FY 2024 where the GIR has been centrally filed in one of the designated 33 jurisdictions and the local GIR notification obligation has been fulfilled. Türkiye is included in this list of 33 jurisdictions. This relief will expire if the exchange has not taken place by 31 December 2026.

4. Strategic Significance for Türkiye

The GIR MCAA completes the international transparency dimension of Türkiye’s participation in the Pillar Two architecture. Türkiye is no longer merely an “implementer” of the global minimum tax. It has become an active member of the information exchange network.

We previously analyzed the investment decision implications of this picture with specific reference to NHMs, see ‘NHM Incentive Looks Attractive in Theory, Pillar Two Tells a Different Story’: the effectiveness of Türkiye’s NHM incentive for large MNEs is constrained by the Pillar Two rules. With the GIR MCAA now in force, this constraint becomes yet more visible. Effective tax rate computations and QDMTT application are now subject to international scrutiny.

5. A Two-Sided Transformation for MNE Groups

At first glance, the Agreement appears to ease the compliance burden: in principle, a single centralized return will suffice, eliminating the need to separately file the same information in dozens of jurisdictions. The GloBE Rules discharge the local filing obligation in jurisdictions where the Agreement is active.

The other side of the coin, however, is this: that single centralized return will be transmitted simultaneously to the tax administrations of all jurisdictions with an active exchange relationship. A single disclosure means simultaneous exposure to multiple tax administrations.

This renders data quality and consistency substantially more critical: an erroneous return filed in Türkiye can trigger a correction process that cascades across the entire network.

6. Signatory Jurisdictions: The Network’s Geography

As of June 2026, the number of jurisdictions that have signed the GIR MCAA has reached 37. The list is predominantly composed of European, G7 and Asia-Pacific economies; the United States has not yet signed.

GIR MCAA Signatories (June 2026)

* Switzerland has signed the Agreement but has not yet completed its domestic approval procedure; it is nevertheless applying the Agreement on a provisional basis pending final ratification.

7. A Notable Nuance: The Diplomatic Relations Reservation

A declaration appended to the Agreement’s signature page by the Republic of Türkiye points to a limitation: Türkiye has declared that it will apply the provisions of the Agreement only towards States Parties with which it has diplomatic relations.

This is a legally valid and commonly used reservation, but it means that active exchange relationships cannot be established with states Türkiye does not recognize.

Looking at the list of signatories, this reservation has concrete practical implications: the Greek Cypriot Administration of Southern Cyprus has signed the Agreement, yet the question arises whether an active exchange relationship can be established between Türkiye and that administration.

8. Conclusion: Transparency Completed, Compliance Journey Begins

The approval of the GIR MCAA is a landmark in the completion of Türkiye’s integrated participation in the global minimum tax architecture. The trajectory from QDMTT to international information exchange demonstrates that Türkiye has embraced OECD tax compliance standards not only in domestic law but on the international stage.

For MNE groups operating in Türkiye, or considering Türkiye as an investment destination, the most critical questions right now are: which jurisdictions will have active exchange relationships, when does the first Reporting Fiscal Year begin, and is existing return preparation infrastructure ready for this new reality?