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Level 1
posted May 28, 2025 10:57:46 AM

Adjusting W-4 for Irregular Income

I also seem to owe a lot of taxes by the end of the year. I also have an irregular income, which changes twice yearly based on the number of classes I'm assigned each semester. I used the IRS tax calculator, but it said that the amount being taken out for taxes was fine. I made a guess as to how much I should take out with better results, but I'd really like to find a more equitable way to figure out my adjustments especially given my constantly changing income. 

 

Thanks.

0 2 1905
2 Replies
Employee Tax Expert
May 28, 2025 11:07:43 AM

Irregular income can be a real challenge to manage, as it is often classified as "supplemental income." Supplemental income is not taxed according to your W-4 form instructions, rather, it is taxed at the supplemental rate (typically 22% federally), often leaving you under withheld.  This article explains more.

A few ways to deal with that is to first determine what tax bracket you are in. While this calculator is for 2024, it can help you figure it out. You can also look at your TurboTax return to see your marginal rate.  While that will be the ending marginal rate (interim income could be lower), it can also help.

If your marginal rate (tax bracket) is above 22%, you can ask your payroll department to withhold at a higher rate, or, if you prefer, you can figure out the difference and send it right to the IRS as an "estimated payment." Here's how you do that.

One thing to be aware of, is that changes you make now will only cover income for the remainder of the year. Consider if you need to do a "catch up" estimated tax payment.

Hope this helps.

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Regards,

Karen

TurboTax Expert

 

Employee Tax Expert
May 28, 2025 11:09:13 AM

Once the Spring semester is complete and you then get Fall work assigned, the best practice would be to project your total income for the year.  You can see the total Federal taxes withheld for Spring and then adjust based on what you expect total year taxes to be.  If your employer is under withholding based on certain assumptions during the Spring, you can go online in December and make an estimated tax payment (make sure it is being apllied to the correct year).