Both a relative and a fixed rate mechanism are applied.
According to article 185/2, § 3, BITC 92, Belgium applies a “low taxation” test with a default relative trigger. It states that foreign entities (PEs or companies) are low-taxed if the foreign income tax is below half of the “theoretical Belgian CIT” (Belgian corporate income tax that would be due if it were established in Belgium and computed under Belgian rules — excluding profits attributable to the foreign entity’s own treaty-exempt PEs). Belgium’s standard nominal CIT rate is 25%, so, for example, the low tax test is satisfied if the foreign income tax is below 12,5% when the theoretical Belgian CIT would be 25%. More generally, the relative trigger equals half of the Belgian-theory rate (e.g., 22% ⇒ 11%).
However, where such foreign entities are established in a non-EEA jurisdiction, the “relative” trigger effectively has a floor because the low-tax condition is deemed satisfied (rebuttable presumption) under the “low or no tax jurisdiction” rule in article 307, § 1/2, BITC 92, which identifies such jurisdictions inter alia by a nominal CIT below 10%. In the same cases, there is also a criterion based on an effective tax on foreign-source income below 15%. In practice, these 10%/15% thresholds operate as fixed reference points for the low-rate assessment of non-EEA jurisdictions.
Besides, the administration clarified in Circular 2024/C/82 (on CFC rules) that a (Q)DMTT collected abroad is not treated as an “income tax” for the CFC low-tax test (i.e., it is ignored when assessing the low-tax condition)."