What might have caused turbo tax to add Form 760C to my Virginia State Tax? There are amounts inserted in these boxes involving spousal tax adjustments, I am single

[ayannasantiago]

Amounts are inserted in Part I in boxes, 1, 2, 4, and 5

[LenaH]

Form 760C is the calculation of your underpayment of Virginia estimated tax for 2023. Virginia law requires that you pay your income tax in timely installments throughout the year by having income tax withheld or by making payments of estimated tax. If you do not pay at least 90% of your tax in this manner, you may be charged an addition to tax. 

As you can see from the screenshot below, the computation of your underpayment uses your income tax liability after spouse tax adjustment (if applicable) and nonrefundable credits (if applicable). This does not necessarily mean you have indicated somewhere on the return that you have a spouse. It just means that if these items were on your return, you would deduct them from your tax liability to compute your underpayment.