(a) In general. (1) Except as otherwise provided in section 3402(f)(6) (see § 31.3402(f)(6)-1), an employee receiving wages will, on any day, be entitled to a withholding allowance as provided in section 3402(f)(1) and paragraph (b) of this section. In order to receive the benefit of the withholding allowance, the employee must furnish to the employer a valid withholding allowance certificate in effect for the calendar year as provided in section 3402(f)(2) and § 31.3402(f)(2)-1.

(2) The employer is not required to ascertain whether the withholding allowance claimed is greater than the withholding allowance to which the employee is entitled. For rules relating to invalid withholding allowance certificates, see § 31.3402(f)(2)-1(f)(3), for rules relating to required submission of copies of certain withholding allowance certificates to the Internal Revenue Service, see § 31.3402(f)(2)-1(g)(1), and for rules relating to the notice of the maximum withholding allowance permitted, see § 31.3402(f)(2)-1(g)(2).

(b) Withholding allowance defined. (1) Generally, the withholding allowance to which an employee is entitled is determined under the computational procedures prescribed by the Commissioner in forms, instructions, publications, and other guidance for the calendar year for which the withholding allowance certificate is in effect.

(2) The withholding allowance is determined based on the following—

(i) Whether the employee is an individual for whom a deduction is allowable with respect to another taxpayer under section 151;

(ii) If the employee is married, whether the employee's spouse is an individual for whom a deduction is allowable with respect to another taxpayer under section 151 but only if such spouse does not have in effect a withholding allowance certificate claiming such deduction;

(iii) If the employee is married, whether the employee's spouse is entitled to additional deductions, credits, or other items the employee elects to take into account under § 31.3402(m)-1 or would be so entitled if the employee's spouse were an employee receiving wages, but only if such spouse does not have in effect a withholding allowance certificate claiming such allowance;

(iv) Any credit under section 24(a) that the employee reasonably expects to be able to claim on the employee's income tax return for the calendar year for which the withholding allowance certificate is in effect, except that the employee may not take into account any credit under section 24(a) if this credit is claimed on another valid withholding allowance certificate in effect with respect to another employer of the employee or the employee's spouse. In addition, an employee whose employer must withhold for that employee pursuant to a notice under § 31.3402(f)(2)-1(g)(2) must offset any tax benefit resulting from a credit under section 24(a) with any anticipated income tax attributable to items other than wages includible in the employee's gross income in the manner prescribed by the Commissioner;

(v) Any additional deductions, credits, or other items the employee elects to take into account under § 31.3402(m)-1 for the calendar year for which the withholding allowance certificate is in effect;

(vi) The basic standard deduction (as defined in section 63(c)(2)) relating to the filing status the employee reasonably expects to claim on the employee's income tax return for the calendar year for which the withholding allowance certificate is in effect; and

(vii) Any adjustment resulting from multiple withholding allowance certificates the employee, the employee's spouse, or both have or reasonably expect to have in effect with respect to one or more employers, determined based on the instructions to the withholding allowance certificate and other guidance for the calendar year for which the withholding allowance certificate is in effect.

(c) Applicability date. The provisions of this section apply on and after October 6, 2020. Taxpayers may choose to apply this section on or after January 1, 2020 and before October 6, 2020. For rules that apply before October 6, 2020, see 26 CFR part 31, revised as of April 1, 2020.