(1) "Tax" means the tax imposed under this part, including interest and penalties under this part, unless the term is given a more limited meaning in the context of this part or a provision of this part.

    (2) "Tax year" means the calendar year, or the fiscal year ending during the calendar year, upon the basis of which the tax base of a taxpayer is computed under this part. If a return is made for a fractional part of a year, tax year means the period for which the return is made. Except for the first return required by this part, a taxpayer's tax year is for the same period as is covered by its federal income tax return. A taxpayer that has a 52- or 53-week tax year beginning not more than 7 days before the end of any month is considered to have a tax year beginning on the first day of the subsequent month.

    (3) "Taxpayer" means a flow-through entity that elects pursuant to section 813 to be subject to the tax under this part.

    (4) "United States person" means that term as defined in section 7701(a)(30) of the internal revenue code.