⚠️ The deadline is now. ⚠️ Employers must begin using new federal withholding tables (available in IRS Pub. 15) by Feb. 15. The new tables reflect the Tax Cuts and Jobs Act, which changed income tax rates, raised the standard deduction and eliminated personal exemptions beginning in 2018. The same deadline applies to changing the withholding on supplemental wages (such as bonuses and commissions) from 25% to 22%. The new tables coordinate with Forms W-4 already filed by employees with their employers to claim withholding allowances.