On 23 March 2022, The Belgian Federal Service for Finance has issued clarifications on the tax consequences of hosting Ukrainian refugees who have fled their country following the invasion by Russia. The main clarifications are
Hosting refugees at home (for free!) does not impact the tax regime of your home. An owner-occupied house continues to be fully tax exempt for income tax purposes. Moreover, the tax advantages of a mortgage to purchase the home are not reduced because of the presence of these refugees.
However, you cannot claim the refugees as dependants, you do not get an additional tax deduction. And singles parents with dependent children, who have a higher personal allowance, will not see tat allowance reduced
The integration income (leefloon, revenu d’intégration) the Ukrainian refugees will receive will be a source of income for the refugees, not for their hosts. If they only received the integration income, they do not pay tax.