Refunding bonds may be issued in a principal amount sufficient to provide funds for the payment of the bonds to be refunded thereby and in addition all expenses incidental to the calling, retiring or payment of such outstanding bonds and the issuance of such refunding bonds.
Source:
Section 6694.3, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=HSC§ionNum=6694.3..