If you have worked and as such have had an income for maximum 475 hours in a calendar year, you will generally only pay a solidarity premium. In this case no tax (in Dutch: ‘bedrijfsvoorheffing’) will be withheld.
Anyone who lives in Belgium for longer than three months must register at the local authority. You will receive a national registration number and will be entitled to reimbursement of taxes if you fall below the income cut-off.
Special case: students from countries bordering Belgium
Students from the Netherlands, Luxembourg, Germany and France should also register at the local authority. Should you stay in Belgium with a so-called “annex 33” (in Dutch: ‘Bijlage 33’), you will not have obtained a national number.
If you want to work in Belgium, you will have to apply for a specific national number, called a ‘bisnummer’. This matter is subject to specific tax regulations.