The TCJA made significant changes to how federal tax is calculated for individual taxpayers. In addition, many of the long-time exemptions no longer apply for tax year 2018 and beyond. These changes make it difficult to estimate the correct amount of tax to withhold from employees’ paychecks. Historically, sensitive information, such as income from sources other than that particular job, wouldn’t be shared with employers.
The TCJA Effects on W-4 Withholdings, Deductions