CA Civ Code Section 8552

If more than one claimant has given a stop payment notice:

(a)

Any number of claimants may join in the same enforcement action.

(b)

If claimants commence separate actions, the court first acquiring jurisdiction may order the actions consolidated.

(c)

On motion of the owner or construction lender the court shall require all claimants to be impleaded in one action, to the end that the rights of all parties may be adjudicated in the action.