What Happens If You Forget to Sign Your W-4 in Step 5?

Form W-4, the Employee’s Withholding Certificate, tells an employer how much federal income tax to withhold from an employee’s pay. It details filing status, dependents, and other adjustments that determine the tax collected each pay period. The final step, Step 5, requires a signature under penalties of perjury to validate the information provided. Without this signature, the IRS considers the form incomplete and invalid.

Employer’s Obligation for an Unsigned W-4

According to IRS regulations, an employer who receives a Form W-4 without a signature must treat it as invalid. This means any information entered in Steps 2 through 4, which detail adjustments for multiple jobs, tax credits for dependents, or other income and deductions, cannot be used by the employer to calculate tax withholding.

The employer’s responsibility is to inform the employee that the form is invalid and request a new, properly completed one. If the employee has a previously submitted, valid W-4 on file, the employer must continue using that version. If no prior valid form exists, they must revert to a default withholding status. This procedure is not optional, as employers must disregard any unsigned or altered W-4 to remain compliant.

Default Tax Withholding Status

If an employee does not provide a valid W-4, the IRS requires the employer to withhold federal income tax at a default rate. This status is “Single” with no other adjustments. The tax calculation will only account for the standard deduction for a single filer, ignoring any dependents, spousal income, or other deductions.

In practical terms, this results in the highest possible amount of tax being withheld from an employee’s paycheck. The withholding tables are structured so that a single filer with no adjustments has more tax taken out compared to someone who is married or claims dependents. This leads to a noticeably smaller take-home pay.

While this reduces immediate cash flow, it typically results in a larger tax refund when they file their annual income tax return. Over-withholding throughout the year means the employee has likely paid more tax than their actual liability. The temporary reduction in net pay continues until a valid W-4 is processed.

Resolving the Missing Signature

Correcting a missing signature requires submitting a new, valid document to the employer. The employee must obtain a new Form W-4, which can be downloaded from the IRS website or provided by their HR or payroll department. It is important to complete all relevant steps accurately, including personal information, filing status, and any adjustments for dependents or other income.

The employee must sign and date the form in Step 5 to validate it, making it legally effective for payroll purposes. Once signed, the completed form must be submitted to the employer, who then has a specific timeframe to implement the new instructions.

According to IRS guidelines, the employer must put the new Form W-4 into effect no later than the start of the first payroll period that ends on or after the 30th day from the date the valid form is received. For example, if a valid form is submitted on June 10th, the employer has until the first payroll period ending on or after July 10th to update the withholding. This means the employee may not see the change in their very next paycheck.