Do the lorries of a Bulgarian haulier have to return to Bulgaria every eight weeks?

No, not any more. The Court of Justice of the European Union annulled that obligation on 4 October 2024, joined cases C-541/20 to C-555/20. Take care when searching the text online: the consolidated version of Regulation (EC) No 1071/2009 on EUR-Lex is dated 21 February 2022 and still carries the annulled obligation word for word. Everything else from the mobility package stands. The separate four-week return rule for drivers applies unchanged, as do the cabotage rules with three journeys in seven days and a four-day cooling-off period.