The PPSA establishes four classes of serial numbered property, being motor vehicles, watercraft, aircraft and certain intellectual property rights (patents, trade marks, designs and plant breeder’s rights).
Security interests over consumer serial numbered property and commercial aircraft must be registered against serial numbers. If not registered against the correct serial number, the general rule is that the registration will be defective, subject to certain "grace periods" where the error in registration against the serial number is not the error or omission of the secured party (for example, the manufacturer subsequently changes the serial number)1. The result is that security interests will become unperfected.
Security interests over other commercial serial numbered property may be registered against its serial number.
Registration against serial numbers is advisable for all serial-numbered property because otherwise security interests are placed on serious risk of extinguishment (under section 44 of the PPSA) if the collateral is transferred2. See Chapter 21 (The extinguishment rules) for further discussion.