Tax Tips Common Tax Mistakes, Not updating your Form W-4 Read the Article Open Share Drawer Share this:Click to share on Facebook (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Pinterest (Opens in new window)Click to print (Opens in new window) Written by TurboTaxBlogTeam Published Dec 18, 2006 - [Updated Mar 28, 2025] 1 min read The purpose of the form W-4 as stated on the IRS instructions is so your employer can withhold the correct federal income tax from your pay. What many people forget is that you should review and possibly update this when you get a promotion or have a life changing event such as a birth, death, marriage or divorce. All of these things can affect how much money you should be withholding from your paycheck to avoid a nasty surprise at the end of the year. Also be sure to review your state withholdings. Your state may take out taxes as a percentage of the federal withholding. If it is a percentage, you may want to increase it or decrease it to balance changes you made to the federal. You can download the W-4 here: http://www.irs.gov/pub/irs-pdf/fw4.pdf Your HR department website may also have a link for you. I would check there first for the state form. There are many paycheck calculators out there to help you with this, including these: http://www.irs.gov/individuals/article/0,,id=96196,00.html http://www.paycheckcity.com/w4/w4instruction.asp We have one on our site with some other calculators as well on our Tax Tips site: https://turbotax.intuit.com/tax_help/index.jhtml You know your small business—we know business taxes. Our self-employed and business tax experts will ensure you get every tax break with 100% accuracy, guaranteed. Start for free 100% free to start. Pay only when you file. Previous Post Avoiding Identity Theft from Phishing Scams Next Post What Is a 401(k) & How Does It Help You… Written by TurboTaxBlogTeam More from TurboTaxBlogTeam Leave a ReplyCancel reply Browse Related Articles Tax Help How to File a Business Tax Extension: Deadlines, Forms, and Penalties Tax Tips The White Lotus Tax Lessons: Navigating Gift Taxes, Lump Sum Payouts, Hush Money, and the IRS Tax Questions What Day Are Taxes Due? April 15! How to File for a Tax Extension or Pay Taxes Online Tax Questions What Happens If You File Your Taxes Wrong? Late Filing Penalties, Interest, and More Tax Questions What’s Tax Deductible? A Guide to Mortgage Interest, Long-Term Care, Funeral Expenses, Student Loans, and Roth IRA Contributions Tax Questions Is it Better to Get Your Taxes Done or Do Them Yourself? (And Other Tax Questions Answered) Tax Forms What is a 1099-K Form? How to Report Payments on Your Tax Return (2024) Tax Forms What is a 1099 Form? A Guide to Understanding Your Tax Obligations Income Tax by State Wisconsin State Income Tax in 2025: A Guide Income Tax by State West Virginia State Income Tax in 2025: A Guide