The Subject-to-Tax Rule (STTR) under Pillar Two: Design, Operation and Implementation

This webinar provides an in-depth analysis of the subject-to-tax rule (STTR), one of the final components of the Inclusive Framework Pillar Two initiative. The STTR is a treaty-based rule granting source jurisdictions the right to “tax back” specific categories of intra-group payments which are subject to nominal tax rates in the state of the recipient lower than the agreed minimum rate of 9%. In other words, the STTR removes potential treaty obstacles to the levying of a top-up tax in the jurisdiction in which the in-scope payments arise. Despite having been conceived in accordance with the overall policy of Pillar Two, the features of the STTR differ significantly from the GloBE rules. This webinar discusses the design, operation and implementation of the STTR, and finally provides a comparison with the subject-to-tax clause currently under discussion at the UN level.


Topics Covered

Block 1: STTR – Policy considerations

Block 2: Scope, covered income and exclusion thresholds

Block 3: Calculation of the adjusted nominal rate

Block 4: Top-up taxes under the STTR and elimination of double taxation

Block 5: Implementation Block 6: The UN subject-to-tax clause

Block 3: Calculation of the adjusted nominal rate

Learning Objectives

After this webinar, the participants will be able to: 

  1. Navigate through the STTR model provision and its commentary
  2. Identify the payments potentially affected by the STTR
  3. Calculate the adjusted nominal rate of taxation for STTR purposes
  4. Evaluate the critical issues deriving from the implementation of STTR


  • Francesco de Lillo (Managing Senior, IBFD) (speaker)
  • Vanessa Arruda (Principal Associate, IBFD) (Facilitator)
  • Carlos Gutiérrez Puente (Principal Associate, IBFD) (speaker)

Field of study


Who should participate

The webinar is suitable for all tax professionals who wish to understand the functioning and impact of the Pillar Two subject-to-tax rule.

Course level and prerequisites

This is an intermediate webinar. Participants in this webinar are expected to be familiar with the key concepts of international tax law and the OECD Pillar Two in particular.

Advance preparation

No advance preparation is needed. Participants are expected to be familiar with the key concepts of international tax law.

Interactive webinar – “Group Internet Based” (live webinar only)

During live webinars, it is possible to interact with the presenters via a chat message function. Please note that questions are answered based on relevance, order of receipt and available time. Additionally, participants in the live webinar are invited to answer poll questions. Participants will also have access to the on-demand version for a further 12 months from the live date.

Date of live broadcast: 26 September 2023

On-demand webinar

On-demand webinars are intended for individual self-study only. Unlike live webinars, they are not open to interactive participation nor do they offer the assistance of a real-time instructor. Access to on-demand webinars is granted for a period of 12 months.

Continuing Professional Education

Many accrediting organizations will grant continuing professional education (CPE) credit(s) for an IBFD audio-visual broadcast. It is advisable, however, that you check with your accrediting body as to whether this applies only to live webinars or to on-demand webinars as well. International Bureau of Fiscal Documentation (IBFD) is registered with the National Association of State Boards of Accountancy (NASBA) as a sponsor of CPE on the National Registry of CPE Sponsors. State boards of accountancy have the final authority on the acceptance of individual courses for CPE credit. Complaints regarding registered sponsors may be submitted to the National Registry of CPE Sponsors through its website: NASBA CPE credit – 1 (only applicable to live webinar).

Webinar registration details

If you have any questions regarding following the webinar, technical requirements, or payments and cancellations, please consult our FAQ.