Hi there and congratulations! You will not be penalized for not updating your W-4 to married. That form is submitted to your employer to tell them how much tax to withhold from your paycheck. It is not a tax return in and of itself. The reason you do want to update it, however, is at the end of the year when you file your tax return if you file Married Filing Jointly, there may not have been enough tax withheld since both of your incomes will be pooled together on one return. Generally, there is more tax withheld for a Single status taxpayer than a Married tax payer, so that's good news for you guys but I would suggest that both of you update your forms and specifically, the one who earns more should carefully fill out Step 2 (as opposed to just checking Married and submitting it) so that enough tax is withheld since you both work. Since we are about to enter June, even if you make the changes right away, you may very well owe something for 2024 but it will be correct for 2025. Obviously, if there are any other changes before next year (ie additional income, getting a raise, etc.), you both should consider if one or both need to update the W-4 again, particularly the higher earner for Step 2 so that the correct amount is withheld. Good luck!
