Iowa Code Title XIV. Property [Chs. 555-594A] § 572.33. Requirement of notification for commercial construction

a. Notifies the general contractor or owner-builder in writing with a one-time notice containing the name, mailing address, and telephone number of the person furnishing the labor or materials, and the name of the subcontractor to whom the labor or materials were furnished, within thirty days of first furnishing labor or materials for which a lien claim may be made. Additional labor or materials furnished by the same person to the same subcontractor for use in the same construction project shall be covered by this notice.

b. Supports the lien claim with a certified statement that the general contractor or owner-builder was notified in writing with a one-time notice containing the name, mailing address, and telephone number of the person furnishing the labor or materials, and the name of the subcontractor to whom the labor or materials were furnished, within thirty days after the labor or materials were first furnished, pursuant to paragraph “a”.