California Code, Probate Code - PROB § 4463

(a) Prepare, sign, and file federal, state, local, and foreign income, gift, payroll, Federal Insurance Contributions Act returns, and other tax returns, claims for refunds, requests for extension of time, petitions regarding tax matters, and any other tax-related documents, including receipts, offers, waivers, consents (including consents and agreements under Internal Revenue Code Section 2032A or any successor section), closing agreements, and any power of attorney required by the Internal Revenue Service or other taxing authority with respect to a tax year upon which the statute of limitations has not run and to the tax year in which the power of attorney was executed and any subsequent tax year.

(b) Pay taxes due, collect refunds, post bonds, receive confidential information, and contest deficiencies determined by the Internal Revenue Service or other taxing authority.

(c) Exercise any election available to the principal under federal, state, local, or foreign tax law.

(d) Act for the principal in all tax matters for all periods before the Internal Revenue Service and any other taxing authority.