Cal. Sts. & Hy. Code § 5390
The warrant, after its delivery to the contractor or his assigns, shall be and constitute full authority to the contractor, his agents or assigns, to collect the assessments.
At least 30 days prior to filing the written statement of all payments received upon the assessment, the contractor, his agents or assigns, shall mail a statement to each owner of real property within the assessment district as shown on the list delivered pursuant to Section 5372.5. The statement shall specify a last date for payment of the assessment, which shall be not less than 30 days from the date of mailing. The statements shall contain a designation of property assessed by the assessment or parcel number shown on the recorded assessment, by street number, or some other description sufficient to enable the property owner to identify the property, a statement of the amount of the assessment, and the place of payment, the effect of failure to pay within such time and that, if bonds are to be issued, a statement of that fact, designating the provisions of law pursuant to which the bonds are to be issued. Upon completion of the mailing of the statements, the contractor or his assigns shall file with the superintendent of streets an affidavit setting forth the date and manner of compliance with the requirements of this section.
On or before the last date for payment specified in the notice, assessments may be paid in whole or in part. No payments shall be received upon the assessment by the contractor, or his agents or assigns, without delivering receipts therefor.
Ca. Sts. and High. Code § 5390