The Lord as Owner of All
Svāmitva ('ownership,' from svāmin = owner, master) is the quality by which Brahman is established as the ultimate owner of all beings and all existence. In Vishishtadvaita, the Lord's svāmitva is not a contingent or granted ownership (as when humans own property through legal title) but an intrinsic, metaphysical reality: the jīvas are constitutively related to the Lord as śeṣa (attribute, servant), and everything the jīva has or is belongs to the Lord.
Svāmitva and Śeṣatva
Svāmitva (the Lord's quality as owner) and śeṣatva (the jīva's quality as owned/servant) are correlative: the Lord's svāmitva implies the jīva's śeṣatva, and vice versa. This pair describes the fundamental ontological relationship between Brahman and all other beings — not as a relationship of tyranny but of love: the owner loves what He owns as His own self.
Implications for the Prapanna
Recognizing the Lord's svāmitva transforms the prapanna's understanding of everything: 'This body is not mine — it is the Lord's instrument; this wealth is not mine — it is the Lord's to be used in His service; this life is not mine — it is the Lord's gift to be employed in His service.' This recognition is both theologically accurate and practically liberating: it removes the burden of self-ownership (mamata).
In Prapatti
The formal act of prapatti includes ātma-nikṣepa (depositing oneself) — which is the explicit, conscious acknowledgment of the Lord's svāmitva. The prapanna says: 'I was always yours; I now acknowledge this openly and offer what was never really mine to withhold.'