Payroll guide for Belgium: Contributions, taxes, and employer obligations

Belgium has no national statute mandating a universal 13th-month bonus. The obligation originates at the sector level through collective bargaining agreements concluded within the relevant Joint Committee. Where a CBA mandates the premium, which covers the overwhelming majority of private-sector employees, the year-end premium typically equals one full month’s gross salary and is paid in December.

Eligibility conditions vary by sector. Under Joint Committee 200 (the fallback committee for most white-collar workers), reforms effective 1 January 2026 grant pro-rata entitlement on resignation after 3 years of seniority, reduced from 5 years, and on dismissal with counter-notice after 6 months. Up to five days of temporary unemployment are now assimilated to working days for premium calculation purposes under JC 200, also effective 1 January 2026.

The year-end premium is subject to employer and employee social security contributions and to professional withholding tax at special “exceptional” rates due to its lump-sum nature.

Double holiday pay is statutory for all private-sector employees and remains one of the more complex parts of Belgian payroll. Vacation entitlement accrues in year X based on work performed in year X-1, known as the holiday service year. The payment itself is an additional supplement, separate from normal vacation salary, equal to 92% of gross salary.

Most employers pay double holiday pay in May or June using the employee’s gross monthly salary at the time of payment, excluding benefits such as company car usage, year-end premiums, meal vouchers, eco-vouchers, and pension contributions.

One distinction frequently missed by foreign employers: white-collar workers receive double holiday pay directly from the employer, while blue-collar workers are paid through a sector-specific vacation fund financed by employer contributions throughout the year.

A landmark reform under the Programme Act of 18 July 2025 introduced a cap on employer social security contributions for high earners. The basic employer contribution (~24.92%) is capped at EUR 85,000 per employee per quarter.

Key mechanics of the cap:

• The EUR 85,000 threshold is a fixed amount, not prorated for part-time employment or incomplete quarters
• Remuneration elements counted: ordinary gross salary, bonuses, and performance-linked salary
• Elements excluded from the cap calculation: pension premiums, company cars, mobility budgets, double holiday pay, severance, profit bonuses
• Other employer contributions (~3%) remain due on total uncapped salary
• Employee contributions of 13.07% also remain fully uncapped
• The threshold is indexed by 2% each time the health index increases by 2%
• The cap is expected to reduce to EUR 67,500 per quarter from 2027, subject to Royal Decree confirmation

The structural reduction is a general reduction of employer social security contributions applied to virtually all employees subject to the full social security regime. The De Wever government reinforced the reduction for low and very low wages from 1 April 2025, with a further update from 1 July 2025. The reduction is highest for employees with low quarterly wages and declines to zero above a ceiling salary.

Employers can combine the structural reduction with one target-group reduction. The most notable is the first-hire reduction: a full employer contribution exemption, capped at EUR 2,000 per quarter, unlimited in duration. Second through fifth hires qualify for a EUR 1,000 per quarter reduction for the first three years. Other target groups include young jobseekers, workers aged 55 and over, and long-term unemployed through Activa programmes. These reductions are managed at the regional level, with Wallonia, Flanders, and Brussels-Capital each administering its own schemes.

The personal tax allowance is EUR 11,180 for income year 2026. This allowance creates a tax reduction equal to 25% of the exempted amount rather than functioning as a zero-rate bracket.

Before withholding tax is calculated, a standard flat-rate professional expense deduction of 30% of gross salary applies, capped at EUR 5,930 for income year 2025. Social security contributions are also fully deductible from taxable income.

Communal tax surcharges are levied by each municipality on the federal income tax base, at rates ranging from roughly 4.9% to 9% depending on residence, with a national average around 7%. The municipality of residence can materially affect an employee’s net pay.

The Annex III tables differentiate withholding tax by family situation and number of dependants. A marital quotient allows up to 30% of the earning spouse’s income (capped at EUR 13,460 for AY 2026) to be attributed to the non-earning spouse, reducing the household tax burden. Dependent children increase the personal tax allowance progressively: EUR 1,980 for the first child, EUR 3,130 for the second, EUR 6,330 for the third, and EUR 7,070 for each additional child. Handicapped dependants count double.

Meal vouchers are one of Belgium’s most widely used salary components. They are issued electronically through licensed providers and are exempt from both social security contributions and withholding tax, provided all conditions are met.

Whether employees receive the higher amount depends on sector- or company-level agreements. The increase is not automatic. A further increase to EUR 12 is anticipated later in the legislative term, though no draft legislation had been published as of May 2026.

Conditions for exemption include: the vouchers must be granted via a CBA or individual written agreement, issued only for each day actually worked (not sick leave, public holidays, or vacation days), delivered electronically, and must not replace existing salary components.

Eco-cheques allow employers to grant up to EUR 250 per employee per year, tax-free and exempt from social security contributions, for environmentally certified goods and services. They must be named, carry a 24-month validity, cannot be cashed, and require a CBA or individual agreement. The De Wever government has announced plans to abolish eco-cheques, potentially replacing their value with higher meal vouchers, but no legislation had been finalised as of May 2026.

The company car remains Belgium’s most common benefit in kind and one of the more complex payroll items to administer. The taxable benefit is calculated using the vehicle’s catalogue value, age depreciation, and CO2 emissions against annually updated reference thresholds. Electric vehicles receive preferential treatment, while a minimum taxable benefit floor applies each year.

Employers must also pay an ONSS/RSZ solidarity contribution on company cars. The contribution increased further in 2026 for vehicles ordered after July 2023 as Belgium continued tightening the tax treatment of higher-emission vehicles.

Another major change from 1 January 2026 is the mandatory availability of the Federal Mobility Budget for employers offering company cars. Employees can exchange the vehicle for a flexible budget covering an electric car, sustainable transport and housing costs, or a partially taxed cash remainder.

The De Wever government approved a temporary partial cap on automatic indexation in December 2025, with draft legislation approved in parliamentary committee on 11 March 2026 and targeted for entry into force 1 June 2026:

• Employees earning up to EUR 4,000 gross per month: full automatic indexation continues unchanged
• Employees earning above EUR 4,000 gross per month: only the first EUR 4,000 is indexed by up to a maximum of 2%; the excess above EUR 4,000 receives no indexation
• A new employer wage-moderation contribution equal to approximately 50% of the employer’s wage cost saving would apply
• For part-time employees, the EUR 4,000 threshold applies to the hypothetical full-time equivalent salary

These measures were still pending a final full parliamentary vote as of May 2026. The Planning Bureau estimated savings of EUR 1.2 billion by 2030 but a 0.35% decrease in household disposable income.

Alongside indexation, a separate ceiling governs real wage increases. The wage norm for 2025-2026 is set at 0% by Royal Decree, meaning the average employer wage cost per employee may not exceed the 2023-2024 level. Individual salary increases are possible, but must be offset elsewhere in the workforce so the company-wide average does not rise. Fines range from EUR 250 to EUR 5,000 per employer, multiplied by the number of affected employees up to 100.

Automatic wage indexation, baremic (seniority-based) scale increases, CBA 90 profit bonuses, and purchasing power premiums are not counted against the 0% norm.

The most difficult compliance issue under the reformed STRIT is the disconnect between income tax and social security treatment. In December 2025, the ONSS/RSZ confirmed that it would not align its social security rules with the revised tax legislation. As a result, the old 30% allowance cap and EUR 90,000 annual ceiling continue to apply for social security purposes, while income tax rules now permit a 35% allowance with no ceiling.

This creates a dual-treatment problem for higher earners. Employees receiving a 35% expatriation allowance on salaries above approximately EUR 257,143 annually will exceed the EUR 90,000 social security threshold. The excess remains exempt from income tax but becomes subject to employee social security contributions at 13.07%.

In practice, payroll teams must operate parallel calculation streams for affected STRIT beneficiaries until the government issues an amending Royal Decree, which had not occurred as of May 2026.

DIMONA is the mandatory electronic registration system for all employment relationships. The DIMONA IN must be submitted before the employee’s first day of work, without exception. DIMONA OUT must be submitted no later than the first working day after termination. The requirement applies to all contract types: fixed-term, open-ended, part-time, interim, student workers, and flexi-job workers.

Foreign employers posting workers to Belgium under an A1 certificate (remaining subject to home-country social security) are not required to file DIMONA. If the worker is subject to Belgian social security, DIMONA applies regardless of the employer’s domicile.

Belgian employers must produce and maintain three key records:

1. Individual account: a comprehensive record of all remuneration paid, hours worked, social security contributions, and withholding taxes deducted, broken down by pay period, quarter, and year.
2. Pay slip: legally required for each payroll period, showing gross salary, all deductions, and net pay.
3. Social balance sheet: an annual statistical report filed by companies with employees, submitted to the National Bank of Belgium within 30 days of approval of annual accounts.

Additionally, the annual Fiche 281.10 (individual tax certificate) summarises total taxable income and withholding taxes for each employee and feeds directly into the personal income tax return.

An estimated 9 out of 10 Belgian companies outsource payroll administration to an accredited social secretariat. These authorised intermediaries calculate gross-to-net payroll, file DIMONA and DmfA declarations, calculate and remit ONSS/RSZ contributions, prepare withholding tax declarations, and issue individual accounts and pay slips. The major operators include SD Worx, Securex, Partena Professional, Acerta, Group S, and Liantis. Foreign employers frequently access social secretariat services through EOR arrangements.