Do you mean you said on a W-4 that you are exempt? Fill out a new W-4 for the employer. The W-4 only goes to the employer to tell them how much to withhold from your paychecks. It does not go to the IRS or dictate how you file your tax return. If you do not have any tax withheld you could end up owing. But if you have been receiving Social Security all year and this is the only other income for 2021 it may not have much affect on your tax for 2021. Going forward, though, it might matter a lot so make sure you get it right.
https://ttlc.intuit.com/community/tax-topics/help/what-to-know-about-the-new-2020-irs-form-w-4-emplo...
https://www.irs.gov/pub/irs-pdf/fw4.pdf
https://www.irs.gov/individuals/tax-withholding-estimator
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
