Begin with an example or your own figures
Select Try an example to load a fictional group, or Use my figures to enter your own prepared data. The examples show a method and stated assumptions; they do not describe your business. Keep the fiscal year and currency consistent. The jurisdiction field is a label, so typing a country name does not automatically select its domestic law or prove that a particular rule applies.
Enter net GloBE income and adjusted covered taxes rather than unadjusted profit and cash tax paid. Choose how to apply the substance-based income exclusion and provide the corresponding inputs. A blank amount is not zero. Review any highlighted field, and use View results to move to the first invalid input or to the result panel.
Select relief only when its conditions are established
The advanced worksheet contains safe-harbour elections and eligibility confirmations. These are facts and decisions you supply; the calculator does not independently verify them. Confirm the applicable collecting rule, period, source data and domestic conditions before using a relief. Read the result explanation as well as the number, because different routes answer different questions.
For example, a fictional team may see tax treated as zero after confirming a safe harbour. That outcome depends on the confirmations being correct. It does not mean the tool has reviewed the group’s accounts, checked an official recognition record for it or removed local reporting duties. If a condition is uncertain, resolve it with the relevant adviser rather than using the checkbox as a prediction.
Use comparison to understand a sensitivity
Open Calculator options and choose Compare a scenario. Scenario B starts from the current figures; change an input and compare the outcomes. The summary shows a signed B-minus-A difference only when the currency and fiscal period match and both outcomes are available. A negative difference indicates a lower estimated top-up tax in B, not a guaranteed saving or a recommendation to restructure.
Open each scenario’s details to review warnings and workings. If changing an amount alters the outcome unexpectedly, check whether a relief, exclusion or threshold also changed. Language switching retains the entered scenarios. Reset and example loading offer a one-level Undo, but the calculator is not a permanent filing record: preserve your source inputs and conclusions separately before navigating away or reloading.
Decide what to do with the estimate
Use the output to identify questions for a fuller review, test sensitivity or explain prepared figures internally. It does not determine group scope, prepare all accounting adjustments, allocate every collecting right or complete a tax return. Where the result is unsupported or depends on uncertain eligibility, bring us the inputs, ownership chart and the question you are trying to answer. We can help identify the next analysis and local confirmation needed before relying on an outcome.
What to do with this
- Enter prepared figures and confirm fiscal year, currency and input definitions.
- Read eligibility messages, assumptions and workings alongside the headline result.
- Use comparisons as sensitivities and retain a separate record for further review.
Official sources and further reading
This article is general commentary on how the rules work. For what a particular jurisdiction has implemented, and from which period, see the jurisdiction guides and their official sources.
Jurisdiction Guides