Planning for the SuedOstLink as an underground cable project started in 2016. To begin, a route corridor grid was determined between Wolmirstedt and Isar. This corridor grid acted as the foundation for the federal sectoral planning (Bundesfachplanung) that was initiated in early 2017. In its decisions regarding the federal sectoral planning, until April 2020 the Federal Network Agency determined a continuous route corridor for further planning.
The SuedOstLink corridor which was established by the Federal Network Agency starts at Wolmirstedt, runs west of Magdeburg towards the south and follows the A14 motorway for about 60 kilometres East of Halle, the corridor branches off from the A14 in southward direction to join the A9 at Bad Dürrenberg and continues to follow in this direction for another 40 or so kilometres. North of Eisenberg, the corridor exits the motorway bundling and runs southward west of Gera, through the Thuringian and Saxon Vogtland. Near Gefell, it reaches the Federal State of Bavaria.
Within this corridor, 50Hertz proposed a routing and local alternatives. These proposal are found in the applications for the planning approval procedure (Planfeststellungsverfahren). The exact course and the development are subject to the ongoing procedure.
Within the guidelines set out in the federal sectoral planning, a number of municipalities have requested to check whether the SuedOstLink can be constructed as an overhead line for their territory. Out of the seven temporary sections, two are subject to ongoing studies. These two partial sections extend from Wolmirstedt to Magdeburg-Olvenstedt in the Börde district and from Welsleben to Förderstedt in the Salzland district.