1. General rule — perfection by filing. Except as otherwise provided in subsection 2 and section 554.9312, subsection 2, a financing statement must be filed to perfect all security interests and agricultural liens.
2. Exceptions — filing not necessary. The filing of a financing statement is not necessary to perfect a security interest:
a. that is perfected under section 554.9308, subsection 4, 5, 6, or 7;
b. that is perfected under section 554.9309 when it attaches;
c. in property subject to a statute, regulation, or treaty described in section 554.9311, subsection 1;
d. in goods in possession of a bailee which is perfected under section 554.9312, subsection 4, paragraph “a” or “b”;
e. in certificated securities, documents, goods, or instruments which is perfected without filing, control, or possession under section 554.9312, subsection 5, 6, or 7;
f. in collateral in the secured party’s possession under section 554.9313;
g. in a certificated security which is perfected by delivery of the security certificate to the secured party under section 554.9313;
h. in controllable accounts, controllable electronic records, controllable payment intangibles, deposit accounts, electronic documents, investment property, or letter-of-credit rights which are perfected by control under section 554.9314;
i. in chattel paper which is perfected by possession and control under section 554.9314A;
j. in proceeds which is perfected under section 554.9315; or
k. that is perfected under section 554.9316.
3. Assignment of perfected security interest. If a secured party assigns a perfected security interest or agricultural lien, a filing under this Article is not required to continue the perfected status of the security interest against creditors of and transferees from the original debtor.