(1) General rule: perfection by filing. Except as otherwise provided in sub. (2) and s. 409.312 (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 s. 409.308 (4) , (5) , (6) , or (7) ;
(b) That is perfected under s. 409.309 when it attaches;
(c) In property subject to a statute, regulation, or treaty described in s. 409.311 (1) ;
(d) In goods in possession of a bailee which is perfected under s. 409.312 (4) (a) or (b) ;
(e) In certificated securities, documents, goods, or instruments which is perfected without filing or possession under s. 409.312 (5) , (6) , or (7) ;
(f) In collateral in the secured party's possession under s. 409.313 ;
(g) In a certificated security which is perfected by delivery of the security certificate to the secured party under s. 409.313 ;
(h) In deposit accounts, electronic chattel paper, investment property, or letter-of-credit rights which is perfected by control under s. 409.314 ;
(i) In proceeds which is perfected under s. 409.315 ; or
(j) That is perfected under s. 409.316 .
(3) Assignment of perfected security interest. If a secured party assigns a perfected security interest or agricultural lien, a filing under this chapter is not required to continue the perfected status of the security interest against creditors of and transferees from the original debtor.