(a) Meaning of terms, in general. — Any term used in this chapter shall have the same meaning as when used in a comparable context in the internal revenue laws of the United States, unless a different meaning is clearly required or unless subsection (b) of this section ascribes a different meaning to such term. Any reference in this chapter to the internal revenue laws of the United States shall mean the Internal Revenue Code of 1986 (26 U.S.C. § 1 et seq.) and amendments thereto and other laws of the United States relating to federal taxes, as the same are or may become effective for the taxable year.

(b) Specific definitions. — Whenever used in this title, the following terms shall have the meanings ascribed to them in this subsection:

(1) “Applicable thresholds” means any dollar figure listed within this title that is used to determine notification requirements, filing frequencies, tax or tax credit calculations that shall be subject to annual adjustment through the application of the threshold adjustment factor, including, without limitation, those specifically set forth in § 515(c)(1) of this title.

(2) “Deficiency” means, in the case of any tax imposed by this title or, where applicable, Title 4, the amount by which such tax so imposed exceeds the excess of:

a. The sum of the amount shown as the tax by the taxpayer upon the return, if a return was made by the taxpayer and an amount was shown as the tax by the taxpayer thereon, plus the amounts previously assessed (or collected without assessment) as a deficiency, over

b. The amount of any abatements, credits or refunds made.

(3) “Director” means the Director of the Division of Revenue or the Secretary of Finance of the State.

(4) “Division of Revenue” means the Division of Revenue of the Department of Finance of the State.

(5) “Internal Revenue Service” means the Internal Revenue Service of the Department of Treasury of the United States.

(6) a. “Last known address,” except as provided in paragraph (b)(6)b. of this section, shall mean:

1. The address for the receipt of mail last made known by the taxpayer to the Division of Revenue on a tax return or written notice; or

2. A mailing address with respect to such taxpayer provided by a service provider to the Division of Revenue.

Whichever address shall have been provided later to the Division of Revenue.

b. Notwithstanding the provisions of paragraph (b)(6)a. of this section, “last known address” shall mean the address determined under paragraph (b)(6)a.1. of this section whenever the taxpayer shows that the address determined under paragraph (b)(6)a.1. of this section is the taxpayer’s actual address and that the address determined under paragraph (b)(6)a.2. of this section is not the taxpayer’s actual address, or that mail sent to the address determined under paragraph (b)(6)a.1. of this section is more likely to reach the taxpayer than mail sent to the address under paragraph (b)(6)a.2. of this section.

(7) “Notice of proposed assessment” means a notice sent to a taxpayer by the Director or the Director’s delegate pursuant to § 521(c) of this title that tax, interest, penalty, additional amount or addition to the tax is proposed for assessment and is due.

(8) “Paid tax preparer” means any person who prepares for compensation, or who employs one or more persons to prepare for compensation, any return or claim for refund, or a substantial portion of any return or claim for refund under this Title. “Paid tax preparer” does not include anyone regulated under Chapter 1 of Title 24.

(9) “Person” means and includes an individual, a trust, estate, partnership, association, company or corporation.

(10) “State” means a state of the United States, the District of Columbia, Puerto Rico, The United States Virgin Islands, or any territory or insular possession subject to the jurisdiction of the United States.

(11) “State Tax Commissioner” means the Director of the Division of Revenue.

(12) “State Tax Department” means the Division of Revenue.

(13) “Tax” shall be deemed also to refer to license fees imposed under Part III of this title.

(14) “This title,” except when used in reference to specific chapters, sections or other provisions of Title 30, shall mean Title 30 of the Delaware Code, except § 3003 and Chapters 51 and 52.

(15) “Threshold adjustment factor” means an amount equal to the Consumer Price Index prepared by the Bureau of Labor Statistics, U.S. Department of Labor for urban consumers, U.S. city average, all items, for the month of June during the year in which an applicable threshold is adjusted, divided by the equivalent Consumer Price Index figure for June 2016.

(16) “Title 4,” for purposes of this chapter, shall be deemed to refer only to subchapter VII of Chapter 5 of Title 4.

68 Del. Laws, c. 187, § 1; 70 Del. Laws, c. 186, § 1; 71 Del. Laws, c. 314, § 6; 80 Del. Laws, c. 195, § 1; 81 Del. Laws, c. 386, § 1.