The W4 is a very basic tax form that doesn’t change much year to year. Although its use is extremely simple, it’s good to know that you can indeed influence the amount of taxes withheld from your wages. It’s your money, and it’s usually better to get it as soon as you can.
The IRS has issued a new Form W-4 and updated its online withholding calculator to reflect this year's revised tax rates and brackets. HR should alert employees to check their tax withholding and to submit a new W-4 if they want to make changes.
Figuring Out Your Form W-4 Under The New Tax Law: How Many Allowances Should You Claim In 2018?