Iowa Code § 636.19: Release.

Such company or corporation may be released from its liability as such surety on any bond on the same terms and conditions, and in the same manner, as is by law prescribed for the release of natural persons as such sureties; it being the intent of this chapter to enable companies created, incorporated, or chartered for such purposes to become surety on bonds required by law, subject to all the rights and liabilities of natural persons.