Short answer. An action for interpleader. Whenever conflicting claims on the same subject matter are or may be made against someone who claims no interest in it, or an interest not disputed by the claimants, that person may sue the conflicting claimants to compel them to interplead and litigate their claims among themselves.
What the law says
Whenever conflicting claims upon the same subject matter are or may be made against a person who claims no interest whatever in the subject matter, or an interest which in whole or in part is not disputed by the claimants, he may bring an action against the conflicting claimants to compel them to interplead and litigate their several claims among themselves.
Rule 62, Section 1 — When interpleader proper. Read the full provision →
The holder has to be genuinely neutral about the outcome
Interpleader is only available to someone who claims no interest whatever in the subject matter, or an interest which in whole or in part is not disputed by the claimants. The person filing the action is not fighting to keep the money or property for themselves — they simply do not know which of the rival claimants is entitled to it, and want the court to decide between them, rather than making that call on their own and risking guessing wrong.
The claims have to genuinely conflict over the same thing
The rule requires conflicting claims upon the same subject matter made, or potentially to be made, against the holder. Two separate, unrelated demands would not fit this description — what triggers interpleader is that satisfying one claimant's demand would necessarily mean denying the other's, because both are asserting a right to the identical money or property, not to two similar but distinct amounts.
What the action actually does
Filing this action lets the holder sue the rival claimants together and compel them to interplead and litigate their several claims among themselves. Rather than the holder deciding on their own who is right and risking being sued by whichever claimant loses out, the court resolves the competing claims directly, with the holder stepping out of the actual dispute over entitlement and simply awaiting the court's determination of who is properly entitled.
Why this protects the person holding the disputed property
Without this option, someone caught between two demanding claimants risks paying or delivering to the wrong one and then facing a second claim from the other. Interpleader lets the holder resolve that exposure in a single proceeding, rather than guessing which claimant to satisfy and hoping not to be proven wrong later by the other, only to end up paying twice over the same underlying obligation.