The Belgian tax year runs from 1 January to 31 December. The tax return for income year 'x' must be filed during the year 'x+1', called the tax year (e.g. income year 2023, tax year 2024). The assessment notice must be sent by the tax authorities by 30 June of the year 'x+2'.
A tax return is sent during the tax year by the tax authorities to be filled in by the taxpayer. An assessment note is sent by the tax authorities within six months following the tax year. Any tax due must be paid to the tax authorities within two months following the sending of the assessment notice.
Spouses and legal cohabitants must file a joined tax return even though their income is taxed separately.
Payment of tax
There is a compulsory income tax withholding (WHT) from salaries (also for directors, now called 'key men').
Professional WHT is due under the following circumstances:
- When remuneration is paid or attributed by Belgian residents, in Belgium or abroad, to Belgian residents or non-residents.
- When remuneration is paid or attributed by Belgian non-residents if the remuneration concerned can be classified as professional expenses, that is, relating to income of the non-resident employer that is taxable in Belgium.
- A new reporting and withholding requirement has been introduced applicable to Belgian companies since 1 January 2019 (reporting) and 1 March 2019 (withholding) for all remuneration and benefits in cash or in kind granted by a related foreign company (e.g. a foreign parent company) to employees/company directors working for the benefit of the Belgian entity. This reporting and withholding obligation applies even if there is no recharge of the costs to Belgium and there is no involvement of the Belgian entity in the grant of the benefit or the management of the plan.
- To calculate the WHT, employers must follow the legal scales as published by the tax authorities.
- All allowances paid to employees as of 1 January 2022 as reimbursement of costs incurred by the employee/director in the framework of the business activity must be justified in the individual tax forms (281.10/281.20) for their actual amount (real value). This reporting obligation concerns all costs to the employer that are reimbursed on the basis of supporting documents.