According to this Agreement, days worked at home solely because of measures taken to combat the Covid-19 pandemic by the Belgian or Luxembourg Governments may be considered as having been worked in the state in which the frontier worker would have been employed if those measures had not been in place.
This exceptional rule does not concern the days during which the cross-border worker would have worked either at home or in a third state, irrespective of these measures. In particular, it does not apply to cross-border workers who, in accordance with their employment contract, generally work at home. The tax treatment of these days of home-based work therefore remains subject to the 24-day tolerance threshold provided for in the agreement of 16 March 2015 (the amicable agreement concluded on the basis of Article 25, s3 of the Belgian-Luxembourg Convention on the prevention of double taxation and on the fiscal treatment of dependent professions).
The new Agreement will apply from 11 March to 30 June 2020.
From 1 July 2020, the application of the Agreement will be extended until the end of the month if both competent authorities agree in writing at least one week before the beginning of the month in question.
More detailed information is available on the website of the Direct Taxation Administration.