Tip:

Farm operators and crew leaders must withhold federal income tax from the wages of farmworkers if the wages are subject to social security and Medicare taxes.

Using Form W-4 to figure withholding.

To know how much federal income tax to withhold from employees’ wages, you should have a Form W-4 on file for each employee. Encourage your employees to file an updated Form W-4 for 2026, especially if they owed taxes or received a large refund when filing their 2025 tax return.

Ask all new employees to give you a signed Form W-4 when they start work. Make the form effective with the first wage payment. If a new employee doesn’t give you a completed Form W-4 in 2026 (including an employee who previously worked for you and was rehired in 2026, and who fails to furnish a Form W-4), treat the new employee as if they had checked the box for Single or Married filing separately in Step 1(c) and made no entries in Step 2, Step 3, or Step 4 of the 2026 Form W-4. An employee who was paid wages before 2020 and who failed to furnish a Form W-4 should continue to be treated as single and claiming zero allowances on a 2019 Form W-4. If you use the optional computational bridge, described earlier under Redesigned Form W-4 , you may treat this employee as if they had checked the box for Single or Married filing separately in Step 1(c), and made no entries in Step 2 and Step 3, an entry of $8,600 in Step 4(a), and an entry of zero in Step 4(b) of the 2026 Form W-4.

Electronic system to receive Form W-4.

You may establish a system to electronically receive Forms W-4 from your employees. See Regulations section 31.3402(f)(5)-1(c) and Pub. 15-T for more information.

Effective date of Form W-4.

A Form W-4 for 2025 or earlier years remains in effect for 2026 unless the employee gives you a 2026 Form W-4. When you receive a new Form W-4 from an employee, don’t adjust withholding for pay periods before the effective date of the new form. If an employee gives you a Form W-4 that replaces an existing Form W-4, begin withholding no later than the start of the first payroll period ending on or after the 30th day from the date when you received the replacement Form W-4. For exceptions, see Exemption from federal income tax withholding , IRS review of requested Forms W-4 , and Invalid Forms W-4 , later in this section.