2023 California Code › Family Code - FAM › DIVISION 2.5 - DOMESTIC PARTNER REGISTRATION › PART 2 - REGISTRATION › Section 298.6.

298.6. (a) Parties to a registered domestic partnership shall not be required to have the same name. Neither party shall be required to change their name. A person’s name shall not change upon registration as a domestic partner unless that person elects to change their name pursuant to subdivision (b).
(b) (1) One party or both parties to a registered domestic partnership may elect to change the middle or last names by which that party wishes to be known after registration of the domestic partnership by entering the new name in the space provided on the Declaration of Domestic Partnership form without intent to defraud.
(2) A person may adopt any of the following middle or last names pursuant to paragraph (1):
(A) The current last name of the other domestic partner.
(B) The last name of either domestic partner given at birth.
(C) A name combining into a single last name all or a segment of the current last name or the last name of either domestic partner given at birth.
(D) A hyphenated combination of last names.
(3) (A) An election by a person to change the person’s name pursuant to paragraph (1) shall serve as a record of the name change. A certified copy of the Declaration of Domestic Partnership containing the new name, or retaining the former name, shall constitute proof that the use of the new name or retention of the former name is lawful.
(B) A certified copy of a Declaration of Domestic Partnership shall be accepted as identification establishing a true, full name for purposes of Section 12800.7 of the Vehicle Code.
(C) This section does not prohibit the Department of Motor Vehicles from accepting as identification other documents establishing a true, full name for purposes of Section 12800.7 of the Vehicle Code. Those documents may include, without limitation, a certified copy of a document that is substantially equivalent to a Certificate of Registered Domestic Partnership that records either of the following:
(i) A legal union of two persons that was validly formed in another jurisdiction and is recognized as a valid domestic partnership in this state pursuant to Section 299.2.
(ii) A legal union of domestic partners as defined by a local jurisdiction pursuant to Section 299.6.
(D) This section shall be applied in a manner consistent with the requirements of Sections 1653.5 and 12801 of the Vehicle Code.
(4) The adoption of a new name, or the choice not to adopt a new name, by means of a Declaration of Domestic Partnership pursuant to paragraph (1) shall not abrogate the right of either party to adopt a different name through usage at a future date, or to petition the superior court for a change of name pursuant to Title 8 (commencing with Section 1275) of Part 3 of the Code of Civil Procedure.
(c) This section does not abrogate the common law right of a person to change the person’s name, or the right of a person to petition the superior court for a change of name pursuant to Title 8 (commencing with Section 1275) of Part 3 of the Code of Civil Procedure.
(Amended by Stats. 2019, Ch. 135, Sec. 5. (SB 30) Effective January 1, 2020.)