Even after the April 15th filing deadline The Franchise Tax Board continues to remind taxpayers to plan ahead to withhold the correct amount of taxes from their paychecks to account for changes in federal tax law.
Controller Betty T. Yee, Chair of the FTB, encourages everyone to take advantage of the Withholding Calculator offered by the IRS to determine if they should adjust withholding to avoid a big tax bill and potential penalties when it comes time to file next tax year returns.
If you need to increase your withholding, the earlier the better! By acting now, you can spread out the tax you pay over the course of 2019 and avoid a bill when you file your 2019 returns in early 2020.
To make any changes, employees should fill out a new Form W-4, Employee’s Withholding Allowance Certificate, and present it to their employer.
https://www.ftb.ca.gov/about-ftb/newsroom/news-articles/use-irs-withholding-calculator-to-avoid-a-tax-bill.html