Here’s the short answer first: Yes—an SPA in the Philippines may validly name multiple attorneys-in-fact. What matters is how you word their authority (joint, several, or a mix) and that the SPA meets the Civil Code and notarial requirements.

What the law says (and how to make it work)

1) You can appoint two or more agents. Philippine agency law allows this. If you appoint several agents and you don’t say they must act “solidarily” (i.e., each fully liable/able to act alone), the default is that their responsibility is not solidary—which in practice means many institutions will treat the mandate as joint, requiring all named agents to sign/act together unless the SPA clearly says otherwise. (Law Library - Legal Resource PH)

2) If several principals appoint one agent, those principals are solidarily liable to the agent. Different scenario, but worth knowing: when two or more principals engage one agent for a common transaction, the principals are solidarily liable to that agent. (This does not change how multiple agents act; it addresses the liability of multiple principals.) (Supra Source)

3) Some acts must be specially and expressly authorized. For high-impact acts (e.g., selling or mortgaging real property, compromising a lawsuit, making extraordinary payments), the Civil Code requires specific, written authority—a “special” power. If your SPA covers one of these, list the act(s) clearly (e.g., identify the property; state price limits; name the case). (ChanRobles)

4) Notarization & execution rules. An SPA should be acknowledged before a notary in the Philippines (the principal must personally appear), or if signed abroad, executed before a Philippine consular officer or a local foreign notary then apostilled/consularized, so it will be recognized and recorded by registries, banks, and agencies. (RESPICIO & CO.)

How to word “multiple persons” correctly

To avoid banks/registries rejecting the document, spell out exactly how the agents may act:

Several authority (any one may act): “I appoint A, B, and C as my attorneys-in-fact, each acting singly with full authority to do any of the acts herein.” (This makes each agent’s act binding without the others; it also implies solidary responsibility among agents only if you say so. Without a solidarity clause, their responsibility to you is not solidary, but third parties can rely on the “singly may act” mandate.) (Law Library - Legal Resource PH)
Joint authority (all must act): “A, B, and C shall act jointly, and all their signatures are required for validity.” (Expect strict compliance—use this only if you truly want a “everyone must sign” rule.) (Law Library - Legal Resource PH)
Hybrid (any two may act; or a primary with alternates): “Any two of A, B, and C may act; if one is unavailable, either of the remaining two may act alone for time-sensitive filings,” or “A is the primary agent; B (and C) may act only if A is unavailable.” (Courts and agencies honor clear limits like this; clarity prevents front-desk refusals.)
Optional solidarity clause (rarely needed): If you want each agent to be solidarily responsible to you for non-performance or for each other’s authorized acts, say so expressly (e.g., “The agents shall be solidarily responsible under Art. 1894”). Use carefully; it increases an agent’s exposure. (Law Library - Legal Resource PH)

Practical checklist (Philippines)

Name the principal and all agents with full IDs (names, gov’t IDs).
State exact powers (and any limits like price caps, specific property). (ChanRobles)
Say whether agents may act singly, jointly, any two, or with succession/alternates. (Law Library - Legal Resource PH)
Include effectivity and revocation language.
Notarize properly (or apostille/consularize if executed abroad). (RESPICIO & CO.)
Bring IDs; some agencies/banks will ask agents to present IDs and the original notarized SPA.

If you want, I can draft a one-page SPA that names multiple attorneys-in-fact and uses whichever mode you prefer (singly / jointly / any two), with the exact powers you need (e.g., sale of a specific parcel of land).