What happened?
Montenegro deposited its instrument of ratification of the Multilateral Convention to Implement Tax Treaty Related Measures to Prevent BEPS in May 2026. The OECD stated at the time that the convention would enter into force for Montenegro on 1 September 2026.
That entry-into-force date has now passed, making the development current even though the ratification announcement itself was published in May.
Key details
The BEPS MLI is designed to modify covered bilateral tax treaties without each treaty having to be renegotiated separately. Its measures can address treaty abuse, permanent-establishment issues and dispute resolution, subject to the choices made by each participating jurisdiction.
The instrument does not produce the same result for every treaty. A bilateral relationship must be checked against each side's covered-tax-agreement listing, reservations and notifications.
Effective date / timing
Entry into force for Montenegro does not mean every affected treaty provision began applying on 1 September. The MLI contains separate rules governing when modifications take effect for particular taxes and treaty relationships.
For transaction-specific analysis, the correct workflow is to identify the treaty, match both jurisdictions' MLI positions and then apply the relevant effective-date rules.
Why it matters
This is exactly the type of treaty event that can be overstated in headline reporting. 'MLI in force' is a jurisdiction-level milestone; the legal result for a taxpayer is bilateral and provision-specific.