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Interest deductibility errors in financial models

The theory of interest deductibility for tax, best practice for modelling it and the errors we find most often, so you can build or review it with confidence.

Webinar · Recording · Presented by Ryan Humphrey · 3 June 2025

Interest deductibility for tax is a complicated and often material part of a financial model. This webinar sets out the theory, recommends best practice and explains why errors in the calculation matter. It aims to give you more confidence when you build or review a model that includes these calculations.

What you will learn

  1. The calculation

    The concept of interest deductibility and the main parts of the calculation, across tax jurisdictions.

  2. Thresholds

    The difference between a threshold set as a percentage of tax EBITDA and a fixed de minimis threshold.

  3. Carried forward balances

    How disallowed interest is carried forward and used in later periods.

  4. Common mistakes

    Examples of the mistakes we see most often in financial models, and how to avoid them.

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