The transfer of interests in a partnership or shares in a corporation is only subject to § 7 para. 7 Inheritance and Gift Tax Act (IGTA), if the transfer is based on a withdrawal of a partner/shareholder by law or partnership agreement/articles of association. A legal acquisition of interests between co-partners or shares between co-shareholders does not come under § 7 para. 7 IGTA.
§ 7 para. 7 IGTA applies if a partner/shareholder leaves a partnership/corporation, that is, he loses the status as partner/shareholder, and the settlement claim lies below the tax value of the interest/share as defined by § 12. This applies mutatis mutandis in case of a redemption of the shares based on a regulation in the articles of association of a GmbH or in case of a voluntary withdrawal of a shareholder, a limitation of transferability clause in the articles of association, or in case of forced cession. Consequently, the remaining shareholders are enriched insofar as the tax value exceeds the settlement. An intention of gratuitousness is not required.
For more details see Koeniger, The German Inheritance and Gift Tax, 2017, p. 68 et seqq.