what type of entity/ an s_corp or partnership? if so, there are rules for an S_Corp shareholder/ S-corp to take the HO deduction or if you were an employee of a partnership that later in the year became a partner and your w-2 was discontinued, then you may be entitled to a HO deduction for the portion of the year you were only a partner (really unclear), if this is your situation again there are specific rules that must be followed.
