Confused about a specific term or acronym? Solve the mysteries of terminology with this informative resource. Updated regularly with industry-specific vocabulary and concepts, the Glossary provides easy-to-understand definitions of tax-related terms.


I9 Immigration and Naturalization Employment Eligibility verification form

ID # Tax Identification Number. See Employer Tax Identification Number (EIN).

Immediate Authorization to Charge See Waiver.

Immediate Wage Withholding Automatic deductions from an employee's wages that start as soon as an agreement for child support is established. See also Wage Withholding.

Immediate Wage Withholding Mandatory deductions from income that start as soon as an agreement for support is established.

Immigration and Naturalization Service (INS) Federal agency charged with enforcement of United States Immigration laws.

Immigration Reform and Control Act of 1986 (IRCA) Law enacted in 1986 that prohibits employers from hiring persons who are not authorized to work in the US and from discriminating against those who are because of national origin or citizenship.

Impound The process of withdrawing funds from a client's account and placing them into an ADP custodial account.

Imputed Income The addition of the value of cash/non-cash compensation to an employees’ taxable wages in order to properly withhold income and employment taxes from the wages.

Independent Contractor An individual, who is self-employed, and is free from the direction and control of an employer covered under state and federal unemployment laws. The Internal Revenue Service uses certain guidelines to determine the independent contractor relationship. Many states utilize the same guidelines. Upon termination of the independent contractor's services, the individual may attempt to collect unemployment benefits. The company should be prepared to prove to the state that the contracted individual was not an employee within the meaning of the law.

Individual Retirement Account (IRA) A tax-deferred retirement account that can be established by any employed person.

Initial Audit This audit assures clients new to ADP-UCS that the most recently assigned SUI tax rate has been calculated correctly. Historical documentation such as charge statements, quarterly tax reports, and 940 forms are required to complete this audit.

Interim Referring to periodic filings and deposits made during a quarter as required by some federal, state, or city agencies.

Interstate Combined-Wage Claim A combined-wage claim in which the paying State is not the State in which the claim is filed and the interstate claims procedures are used in making the payment.

Inverse Chronological Order This benefit charging method combines the prorating and most recent employer methods. Each base period employer's liability is calculated using the prorating method, rather than charging all employers simultaneously. States using the inverse chronological method charge the most recent employer until its liability has been exhausted. The next most recent employer is then charged, and so on.

Invoice A document that notifies an ADP client of charges and credits to their bank account.

Invoice Address The mailing address where ADP Tax Filing Service clients want to receive their invoices.

Involuntary Deductions Deductions over which the employers and employees have no control.

IRA See Individual Retirement Account.

IRS Internal Revenue Service.