Our disquisition in Municipality of Biñan v. Garcia is definitive. There, we explained that the determination as to the existence of co-ownership is necessary in the resolution of an action for partition. Thus:
The first phase of a partition and/or accounting suit is taken up with the determination of whether or not a co-ownership in fact exists, and a partition is proper (i.e., not otherwise legally proscribed) and may be made by voluntary agreement of all the parties interested in the property. This phase may end with a declaration that plaintiff is not entitled to have a partition either because a co-ownership does not exist, or partition is legally prohibited. It may end, on the other hand, with an adjudgment that a co-ownership does in truth exist, partition is proper in the premises and an accounting of rents and profits received by the defendant from the real estate in question is in order. x x x
The second phase commences when it appears that “the parties are unable to agree upon the partition” directed by the court. In that event[,] partition shall be done for the parties by the [c]ourt with the assistance of not more than three (3) commissioners. This second stage may well also deal with the rendition of the accounting itself and its approval by the [c]ourt after the parties have been accorded opportunity to be heard thereon, and an award for the recovery by the party or parties thereto entitled of their just share in the rents and profits of the real estate in question. x x x (Emphasis supplied.)
While it is true that the complaint involved here is one for partition, the same is premised on the existence or non-existence of co-ownership between the parties. Petitioner insists she is a co-owner pro indiviso of the five real estate properties based on the transfer certificates of title (TCTs) covering the subject properties. Respondent maintains otherwise. Indubitably, therefore, until and unless this issue of co-ownership is definitely and finally resolved, it would be premature to effect a partition of the disputed properties. More importantly, the complaint will not even lie if the claimant, or petitioner in this case, does not even have any rightful interest over the subject properties.