Good news for all those who need a little longer:
Cross-border commuters with foreign income still have until 18 October 2023 to file their Belgian tax return for 2022. The condition is that they fill it out online via Tax-on-Web. This service can be used via the Belgian financial portal MyMinFin.
Apart from income from abroad, the separately limited so-called specific income also includes income from self-employment.
Note: The paper version must still be submitted by 30 June 2023.
Online filing of tax returns is possible for everyone in Belgium
According to the Belgian Ministry of Finance, an online tax return is possible for everyone, even if one has received a paper return.
Simplified return proposals can also be viewed and amended online.
Source: https://finance.belgium.be/en/private-individuals/tax-return/return/submitting-your-tax-return#q1