{ "country": "Belgium", "country_code": "BE", "version": "2026-04", "effective_from": "2026-04-01", "status": "prototype_v1_structural_reduction", "currency": "EUR", "wage_reference": { "name": "GGMMI / RMMMG", "gross_monthly_eur": 2189.81, "weekly_hours": 38, "source": "CNT / NAR minimum wage reference", "note": "Belgian national minimum wage reference for full-time private-sector employees. Sectoral minima may be higher." }, "grid": { "min_multiple": 0.80, "max_multiple": 6.00, "step": 0.01 }, "social_security": { "employee_contribution_rate": 0.1307, "employer_base_contribution_rate": 0.25, "employee_contribution_note": "Standard employee ONSS contribution rate for private-sector employees.", "employer_contribution_note": "Base employer contribution rate for the private market sector before reductions.", "employee_contribution_branches": { "pension": 0.0750, "sante_soins": 0.0355, "sante_indemnites": 0.0115, "chomage": 0.0087, "note": "Sous-taux ONSS par branche (retraite, assurance maladie-invalidite - soins de sante, assurance maladie-invalidite - indemnites, chomage), somme exactement egale au taux global de 13,07 %. Source : instructions administratives ONSS (socialsecurity.be/employer/instructions/dmfa)." }, "employer_contribution_branches": { "pension": 0.0886, "sante_soins": 0.0380, "sante_indemnites": 0.0235, "chomage": 0.0146, "maladies_professionnelles": 0.0100, "accidents_travail": 0.0030, "residuel": 0.0723, "note": "Sous-taux ONSS par branche (retraite, assurance maladie-invalidite - soins de sante, assurance maladie-invalidite - indemnites, chomage, maladies professionnelles, accidents du travail), issus des instructions administratives ONSS (socialsecurity.be/employer/instructions/dmfa). Ces six branches sourcees directement totalisent 17,77 points ; le residuel de 7,23 points (jusqu'au taux de base de 25,00 %) regroupe les allocations familiales (regionalisees depuis 2015 mais toujours consolidees dans le taux de base ONSS) et des cotisations diverses de moindre montant (conge-education paye, plan d'accompagnement, accueil des enfants, etc.) qui n'ont pas pu etre individuellement verifiees aupres d'une source primaire dans le cadre de cette recherche -- ce residuel est donc une valeur derivee (25,00 % moins les six branches sourcees), pas une valeur sourcee independamment." }, "structural_reduction": { "active": true, "category": 1, "period": "2026-Q2", "dmfa_reduction_code": 3000, "mu": 1.0, "beta_s": 1.0, "low_wage_component_rate": 0.1400, "low_wage_threshold_quarterly_eur": 11458.57, "very_low_wage_component_rate": 0.1600, "very_low_wage_threshold_quarterly_eur": 9547.20, "source": "ONSS / RSZ administrative instructions 2026/2, structural reduction, category 1", "note": "Prototype full-time monthly implementation. The quarterly reference wage S is approximated as gross monthly wage multiplied by 3. Negative components are set to zero." }, "structural_reduction_category_2": { "active": true, "category": 2, "period": "2026-Q2", "mu": 1.0, "beta_s": 1.0, "base_amount_quarterly_eur": 79.00, "low_wage_component_rate": 0.2300, "low_wage_threshold_quarterly_eur": 9975.60, "very_low_wage_component_rate": 0.1600, "very_low_wage_threshold_quarterly_eur": 9975.60, "high_wage_component_rate": 0.0600, "high_wage_threshold_quarterly_eur": 16803.98, "source": "ONSS / RSZ administrative instructions 2026/2, structural reduction, category 2 (secteur non-marchand / Maribel social), https://www.socialsecurity.be/employer/instructions/dmfa/fr/latest/instructions/deductions/structuralreduction_targetgroupreductions/structuralreduction.html", "note": "Prototype full-time monthly implementation. Formula: base + low_wage_component_rate x (low_wage_threshold - S) + very_low_wage_component_rate x (very_low_wage_threshold - S) + high_wage_component_rate x (S - high_wage_threshold), each term floored at 0 before summing (same convention as category 1). IMPORTANT SIMPLIFICATION: the official formula's high-wage term uses W, the employer's total quarterly payroll mass (masse salariale trimestrielle) -- a firm-level aggregate specific to the Maribel social funding mechanism, not the individual worker's own wage. Since this module simulates a single representative employee rather than a firm, W is approximated as equal to S (this employee's own quarterly wage), the same single-employee simplification already used throughout this module. This is a best-effort implementation of a structurally complex, firm-level formula; category 2 results should be treated as indicative." } }, "profiles": [ { "profile_id": "belgium__standard_private_sector", "label_fr": "Belgique · secteur privé standard", "label_en": "Belgium · standard private sector", "structural_reduction_category": 1, "employee_contribution_rate": 0.1307, "employer_contribution_rate": 0.25 }, { "profile_id": "belgium__non_profit_sector", "label_fr": "Belgique · secteur non-marchand (Maribel social)", "label_en": "Belgium · non-profit sector (Maribel social)", "structural_reduction_category": 2, "employee_contribution_rate": 0.1307, "employer_contribution_rate": 0.25 } ], "limits": [ "Personal income tax withholding (precompte professionnel) is simulated for a single, childless resident taxpayer with no other income or deductions; other personal-tax-return mechanisms (joint assessment, dependants, other tax credits) are not modeled -- see analysis/belgium/precompte_professionnel_2026.py.", "The structural reduction is simulated for category 1 (general private sector) and category 2 (secteur non-marchand / Maribel social) using a simplified full-time monthly implementation. Category 2's high-wage component depends on the employer's total payroll mass in the official formula; this module approximates it with the single simulated employee's own wage, since no firm-level aggregate is modeled.", "The quarterly reference wage S is approximated as monthly gross wage multiplied by 3.", "Sectoral minimum wages are not simulated.", "Sector-specific employer contributions are not simulated.", "Manual-worker holiday pay contributions are not simulated.", "Regional and family-status differences are not simulated.", "Employer contribution rate is treated as a simplified base rate before structural reduction." ] }