Legal Question in Administrative Law in California

Probably not. Just like writing two checks, the powers of attorney will supplement each other in most cases. The earlier power of attorney should be revoked to avoid problems. If each is given to the same attorney-in-fact, however, the later power of attorney is probably effective to modify conflicting provisions in the earlier power of attorney.

Not all powers of attorney work the same, but in general a power of attorney can be revoked by death of the principal, by express notice of revocation or termination to the attorney-in-fact, or by the occurrence of an event set forth in the power of attorney (such as the end of the year).

For termination and revocation provisions see Probate Code sections 4151, 4152 and 4153.

Note that the law makes a distinction between revocation of the power of attorney as a whole and termination of the authority of the attorney-in-fact.

Also, the revocation rules for health care powers of attorney are different - see Probate Code sections 4695 to 4698. With these, a later directive will cancel an earlier directive to the extent of any conflict between them.