Ex-officio tax relief – Extended application and clarification of the concept of ‘material error’


Within six months (as from the third working day) following the date of sending of the tax assessment notice by the Belgian tax authorities, taxpayers can file a tax claim in order to obtain a rectification.

After this six-month period has expired, a rectification in case of surtax can in some cases be requested via an ex-officio tax relief during a five-year period. This is for example possible in the following cases:

–       In the case where a tax reduction was not claimed or granted;

–       in the case where a ‘material error’ was made when filing the tax return or when establishing the taxes due.

Due to a change in the tax law in December 2013, the list of tax reductions eligible for such ex-officio tax relief was significantly extended as from tax year 2014 (income of 2013).

Recently, the Belgian tax authorities have published a Practice Note including a list of all eligible tax reductions. They have also clarified the notion of ‘material error’ with specific examples of (non-)qualifying material errors. It is e.g. explicitly stated that wrongfully declaring foreign-source income as Belgian-source income, does not constitute a material error.