Tax Deduction and Collection Account Number requirement mandates application, mandatory quoting on tax documents and penalises noncompliance. Every person required to deduct or collect tax must apply to the Assessing Officer for allotment of a Tax Deduction and Collection Account Number within one month of the month in which tax was deducted or collected, by submitting Form 49B in duplicate. The allotted number must be quoted in all challans for payment, certificates, statements and other prescribed documents. Centrally notified exceptions exist. Failure to obtain or to quote correctly, or quoting a number known or believed to be false, attracts a prescribed penalty imposed by the Assessing Officer after an opportunity of hearing.