CA 540 line 12, but this number is not used anywhere else, why?

[shiyi11]

I put my number in there, sure, no problem.

But it gets me wondering why? I don't see this number used anywhere in my return. Why ask us to put a number in but there is no refer to it anymore?

CA tax are calculated using Line 13-19

I dont get it, if anyone know anything, thanks!

Taxable Income

Refer to your completed federal income tax return to complete this section.

Line 12 – State Wages

Enter the total amount of your state wages from all states from each of your federal Form(s) W-2, Wage and Tax Statement. This amount appears on federal Form W-2, box 16.

[MonikaK1 · Accepted solution]

TurboTax will enter the California wages on Line 12 of California Form 540 based on your W-2 entries. 

The form is designed that way by the State of California tax agency. As you noted, this figure is displayed to the side of the other entries and is not part of the calculations in the column to the right. The California Franchise Tax Board may be using this figure as a checkpoint in their review process.