The owner of record for a fiscal year is the owner on January 1 of the calendar year that the fiscal year begins. It is critical to send the bill to the 1/1 owner to preserve their assessment rights. Any subsequent deed transfers to the 1/1 date are obviously necessary to track so we always know who the current owner is, but the burden is on the homeowner to know that they own a property and to do their due diligence when they obtain said property to inquire as to when the bills will be due and what amount is owed. Please see MGL Ch59 sec 11 where 1/1 record owner liabilities are laid out but also MGL Ch60 sec3 where the option to notify a subsequent owner is offered:
"The collector may send the notice required by this section to an owner who has acquired title by a deed duly recorded subsequent to January first in the year in which said tax was assessed."