Legal practice often encounters the desire of the owner to split his right to a thing to form shares and to alienate them or to split the share in the right to joint property for the same purpose. The possibility of splitting the right to sole property to form joint property is often questioned, since its emergence is associated only with the transfer of an indivisible item into the ownership of two or more persons. Other grounds, including such as the split-up of the right, are denied. In fact, the split-up of the right to sole property by the unilateral expression of the will of its holder is possible if it involves simultaneous transfer of the newly formed share to the third party. Such a disposal arrangement should be seen as the alienation of a thing to the ownership of the collective, to which the former owner is a party. The split-up of the share is also possible. Such an act should be regarded as an extension of the number of participants. To extend the number of participants, the consent of all co-owners is needed.