How to run payroll in Belgium

In Belgium, most employers pay employees monthly, typically on the last working day of the month. Here's the complete payroll cycle.

Payment frequency and timing

Belgian law requires monthly salary payments for most employees, though weekly or bi-weekly payments are permitted for certain worker categories like temporary staff.

The standard practice is paying on the last working day of each month. Some companies choose the 25th or 28th to allow processing time, but payment can't be later than the month's end.

For hourly workers, payment must occur within one month of the work period. Many employers pay these workers bi-weekly or weekly to maintain cash flow.

13th month payment

Belgium has a mandatory 13th month payment called "treizième mois" in French or "dertiende maand" in Dutch. This isn't optional - it's a legal requirement.

The 13th month equals one month's gross salary and is typically paid in December, though some companies split it between June and December. It's subject to the same tax and social security contributions as regular wages.

Holiday pay calculation

Belgian employees receive vacation pay equal to 92% of their gross salary for the vacation days earned in the previous year. This is paid by the National Office for Annual Holidays (ONVA) for blue-collar workers and directly by employers for white-collar workers.

Vacation pay is distributed in two parts:

• Single vacation allowance: Paid in May (around €250-€500 depending on family situation)
• Double vacation allowance: Paid in June (main vacation pay amount)

The calculation uses the previous year's earnings, so 2026 vacation pay is based on 2025 wages.

Payment methods and requirements

Bank transfers are mandatory for all salary payments in Belgium. Cash payments aren't permitted for regular wages, and checks are rarely used.

International companies must ensure payments reach Belgian bank accounts in euros. Currency conversion costs can be deducted from wages only with explicit employee consent.

Employers must provide payment within the agreed timeframe - delays can result in penalty interest of 7% annually, plus potential labor inspection fines.

Payslip requirements

Belgian payslips must include extensive detail and be provided in Dutch, French, or German depending on the region. Electronic payslips are acceptable with employee consent.

The payslip must clearly separate different wage components like base salary, overtime, bonuses, and benefits. All social security contributions and tax withholdings need individual line items.

Think you just withhold federal tax? Belgium adds regional and communal taxes that catch many employers off guard.

Your employees face a progressive income tax system with rates from 25% to 50%, plus regional taxes that vary by location. The complexity comes from Belgium's three-tier system: federal, regional, and communal taxes all get bundled into one withholding calculation.

Income tax brackets

Belgium's federal income tax uses these brackets for 2026:

But that's just federal tax. Regional taxes add another 6.75% to 11.75% depending on the region, and communal taxes range from 0% to 11.5%. A Brussels employee might pay an effective top rate of 61.25% when you combine all three levels.

The monthly equivalent thresholds are €1,267 for the 40% bracket and €3,870 for the top 50% rate.

Withholding requirements

You're responsible for calculating and withholding all income taxes from employee pay. This includes federal, regional, and communal taxes in one combined deduction.

Register for payroll tax through the National Social Security Office (NSSO) before your first payroll run. You'll need your company registration number and employee details.

Monthly withholding tax returns are due by the 15th of the following month. Pay the withheld taxes by the same deadline to avoid penalties.

Annual reconciliation happens through the 281.10 forms, due by February 28th for the previous tax year. Employees use these forms for their personal tax returns.

Tax registration

New employers need three key registrations:

• NSSO registration for social security and payroll taxes
• VAT number from the Federal Public Service Finance
• Dimona declarations for each employee before they start work

Allow 2-3 weeks for initial registrations. The NSSO handles most payroll-related registrations, but you'll interact with multiple agencies for complete compliance.

Special tax considerations

Non-resident employees face different withholding rates. EU residents get the standard progressive rates, but non-EU residents pay a flat 33% withholding rate unless they elect for progressive taxation.

Belgium's extensive tax treaty network can reduce withholding for temporary assignments. The 183-day rule applies for most treaties, but documentation requirements are strict.

Expatriate tax regimes offer reduced rates for qualifying foreign executives and researchers. The expat tax regime caps income tax at 11.5% for qualifying individuals, but requires advance approval.

Regional differences matter more than most countries. A Wallonia employee pays 6.75% regional tax while a Brussels employee pays 10.75% - that's a 4% difference in total tax burden.

Common tax mistakes

Wrong regional tax rates top the list. Using Brussels rates for a Flanders employee creates immediate compliance issues. Verify each employee's commune code and apply the correct regional and communal rates.

Missing monthly deadlines triggers automatic penalties of 10% of the tax due, minimum €50 per month. Late payments add 0.8% interest per month.

Incorrect non-resident treatment causes major problems. Applying resident rates to non-EU employees or missing treaty benefits both create audit risks and employee complaints.

Annual reconciliation errors on 281.10 forms delay employee tax refunds and trigger review requests. Double-check social security numbers, addresses, and income calculations before filing.

Employer contributions in Belgium add 35% to every salary. Budget for it.

Belgium's social security system requires substantial employer contributions across multiple categories. These contributions fund employee benefits like healthcare, unemployment insurance, and pensions.

Contribution breakdown

The largest piece is social security at 25%, which covers healthcare, family allowances, and unemployment benefits. Annual holiday pay at 10.27% is unique to Belgium and funds the mandatory vacation bonus.

Total employer cost example

For a €60,000 annual salary:

• Base salary: €60,000
• Social security: €15,000
• Holiday pay: €6,162
• Occupational accidents: €180
• Professional diseases: €690
• Closing down fund: €156
• Total employer cost: €82,188
• Cost multiplier: 1.37

Your actual payroll cost is 37% higher than the gross salary. This percentage varies slightly based on sector-specific rates for occupational accidents and diseases.

Contribution caps and ceilings

Social security contributions cap at €67,200 in 2026. For salaries above this threshold, you'll pay maximum social security of €16,800 annually.

Holiday pay and other contributions have no caps. High earners still generate the full percentage on their entire salary for these items.

The cap creates a decreasing effective rate for executives. A €100,000 salary has a total employer rate of 33% instead of 37%.

Registration requirements

Register with the National Social Security Office (ONSS/RSZ) before hiring your first employee. You'll receive a unique employer number for all contribution payments.

Submit these documents:

• Company registration certificate
• VAT number
• Employment contracts
• Workplace risk assessment

Registration takes 5-10 business days. Late registration triggers penalties of €250-€2,500 depending on delay duration.

Payment deadlines

Quarterly contributions are due by the 15th of the month following each quarter:

• Q1 (Jan-Mar): Due April 15
• Q2 (Apr-Jun): Due July 15
• Q3 (Jul-Sep): Due October 15
• Q4 (Oct-Dec): Due January 15

Monthly filers pay by the 15th of the following month. Companies with over €4 million in annual contributions must file monthly.

Pay through electronic transfer to ONSS. Paper submissions aren't accepted for companies established after 2020.

Belgium has 11 public holidays in 2026. Work on these days? Pay double.

Belgium's leave and benefits system affects your payroll calculations in specific ways. From vacation accruals to sick pay splits between employer and social security, here's what impacts your monthly processing.

Annual leave

Belgian employees get 20 working days of paid vacation per year. That's four weeks minimum, but most collective agreements bump it to 25+ days.

Vacation pay gets tricky. Employees earn vacation pay based on previous year's salary. In 2026, they're paid vacation money based on what they earned in 2025. New employees get an advance that's reconciled later.

Carryover rules: Unused vacation expires after 15 months. Employees can carry over days into the next year, but they must use them by March 31st or lose them.

Termination payouts: You must pay unused vacation days at termination. Calculate based on current salary, not the previous year rate used for regular vacation pay.

Sick leave

Sick employees get guaranteed salary for the first 30 days, but who pays depends on timing.

Employer pays: First day (waiting day) gets no pay unless your collective agreement says otherwise. Days 2-30 are paid at 100% by you.

Social security pays: From day 31 onwards, social security takes over at 60% of salary (up to €2,754 monthly maximum in 2026).

Medical certificates: Required from day 1 of absence. No exceptions. Employees must send the certificate within 48 hours or risk losing pay.

Parental leave

Maternity leave: 15 weeks total. First week is paid by employer at 100%. Remaining 14 weeks are paid by social security at 82% of salary (capped at €3,284 monthly in 2026).

Paternity leave: 20 days within four months of birth. First three days are paid by employer at 100%. Remaining 17 days are paid by social security at 82% of salary.

Payroll impact: You'll process reduced social security payments and handle the employer-paid portions. Employees on social security leave still accrue vacation days.

Public holidays 2026

Regional variation: Flanders and Brussels get Boxing Day. Wallonia doesn't. Check your employee locations.

Overtime rates: Work on public holidays triggers double pay (200% of normal rate). No exceptions.

Mandatory benefits affecting payroll

13th month bonus: Most collective agreements require a 13th month payment in December. This isn't legally mandated but affects 90%+ of employees. Budget an extra month of gross salary.

Meal vouchers: Not mandatory but standard. Employer pays €4-6 per voucher, employee contributes €1.09 minimum. These are tax-free up to €8 per day.

Company car benefits: Taxable benefit calculated at 6.25% of catalog value annually for 2026. This creates additional taxable income on payroll.

Group insurance: Many companies provide supplementary pensions. Employer contributions are deductible, but employee contributions come through payroll deductions.

The key is tracking these benefits monthly. Meal vouchers, company cars, and insurance all affect your tax calculations and social security contributions.

Employment contracts in Belgium must include 14 mandatory elements or they're legally invalid. Missing items like the exact workplace address, detailed job description, or trial period terms can trigger labor inspections and fines starting at €400 per violation.

What are the monthly filing requirements?

Belgium requires monthly social security filings through the DmfA declaration system. You'll submit employee data and contribution calculations by the 15th of the following month.

The DmfA filing includes:

• Employee identification and salary details
• Working time and leave taken
• Social security contributions calculated
• Any salary adjustments or bonuses paid

Submit everything through the Belcotax-on-web portal. Late filings trigger automatic penalties of €50 per employee, capped at €2,500 per declaration.

Monthly tax withholding gets paid simultaneously with social security contributions. The combined payment deadline is the 15th of the following month for companies with monthly obligations.

What annual reporting is required?

Year-end reconciliation happens through the 281.10 forms for each employee, due by March 31, 2026. These forms detail total gross salary, taxes withheld, and benefits provided during 2025.

You'll also file the 274.10 summary declaration listing all 281.10 forms submitted. This acts as your annual reconciliation with the tax authorities.

Employee tax certificates must be distributed by February 28, 2026. Employees need these to complete their personal tax returns by June 30, 2026.

The annual social security reconciliation compares your monthly DmfA filings with actual payments made. Submit this through Belcotax-on-web by March 31, 2026.

What employee documentation is required?

Employment contracts must be written in Dutch, French, or German depending on the region. Include these 14 mandatory elements:

• Employee and employer identification
• Workplace address and job description
• Start date and contract duration
• Working hours and schedule
• Salary amount and payment frequency
• Trial period terms (maximum 12 months)
• Notice periods and termination conditions

Monthly payslips require 23 specific elements including gross salary breakdown, each deduction itemized, net pay calculation, and year-to-date totals. Missing elements trigger fines of €125 per payslip.

Record retention spans 30 years for individual employee accounts and 10 years for supporting payroll documentation. Digital storage is acceptable if you maintain backup systems.

What are the penalties for non-compliance?

Repeat violations double the base penalties. Three violations within 12 months can trigger enhanced monitoring requiring monthly compliance reports.

Criminal penalties apply for intentional tax evasion exceeding €25,000, with potential prison sentences up to 5 years.

Which regulatory bodies oversee payroll?

Federal Public Service Finance handles income tax compliance and withholding obligations. Access their services through MyMinFin portal at myminfin.belgique.be.

National Social Security Office (RSZ/ONSS) manages social security contributions and DmfA filings. Use their Student@Work and Limosa portals for specific worker categories.

Regional employment services oversee work permits and labor law compliance:

• VDAB for Flanders
• Actiris for Brussels
• Le Forem for Wallonia

Federal Public Service Employment enforces labor law compliance through workplace inspections. They can audit payroll records, employment contracts, and working time documentation without advance notice.

Contact the Social Inspection Service at 02 233 41 11 for compliance questions or to report suspected violations.

2026 brought several important payroll changes to Belgium. Here's what you need to update.

Minimum wage increase - Effective January 1, 2026 Belgium's national minimum wage increased to €1,842.28 per month (€12.57 per hour), up from €1,806.00 in 2025. This 2% increase affects approximately 180,000 workers across the country.

All employers must update their payroll systems to reflect the new rates. Review your current wage structures to ensure compliance, especially for part-time and temporary workers.

Social security contribution adjustments - Effective January 1, 2026 Employee social security contributions remain at 13.07% of gross salary, but the contribution ceiling increased to €66,600 annually (up from €65,400 in 2025).

Employer contributions stayed at 25% of gross salary, but the higher ceiling means increased costs for high earners. Update your payroll calculations to reflect the new maximum contribution amounts.

Withholding tax bracket updates - Effective January 1, 2026 Tax brackets were adjusted for inflation with a 2.1% indexation. The tax-free threshold increased to €10,570 (from €10,350), and all bracket thresholds moved up proportionally.

These changes reduce the tax burden for most employees. Update your withholding calculations immediately to avoid over-withholding employee taxes.

Digital payslip requirements - Effective July 1, 2026 Starting mid-2026, all employers must offer digital payslips through secure online portals. Paper payslips remain acceptable only if employees specifically request them in writing.

Upcoming changes for 2027 Belgium announced plans to introduce mandatory pension contribution increases starting January 2027. Employee contributions will rise from 7.5% to 8% of gross salary, with employers covering an additional 0.5%.

Start budgeting for these changes now and communicate the upcoming adjustments to your Belgian workforce during 2026 planning cycles.