"CASDI" and "540X" questions.

No. Schedule A Line 5. It qualifies as a state income tax.

The base period of limitations for California personal income tax is 4 years (1 year more than federal) from the later of time of filing or due date.

That was what I thought so, but when I google it over the internet, I do see someone's advise to have it on "Schedule A", Line 8. Either Line 5 or Line 8, that will not make any difference for my Federal tax return, but will affect the amount of my State tax return .

Is there some official website I may take a look ?

Thanks a lot

-c

There is only one correct place for CSDI and that is line 5, not line 8.

Yes.

To be specific you don't have to look any further than the instructions for the 1040 schedule A, line 5 on page 2-A of the instructions (it's covered in the forth bullet).

The instructions for California 540 are pretty official. SDI (but not VPDI, because it is voluntary rather than mandatory) goes on federal Schedule A, line 5. It is deductible federally as a "local" income tax, but of course does not count as an actual payment toward your California state income tax. (As a side note, if you have two or more employers who over-withhold SDI/VPDI for the year, you get a refund of the excess, just like Social Security at the federal level).

When you look at your CA itemized deductions on page 2 of Schedule CA(540), you will see that both state income tax (or sales tax) and SDI are subtracted from CA itemized deductions.

I recall reading that SDI is deductible due to the outcome of a tax court case challenging the IRS (only a few states have a mandatory disability insurance tax withheld from wages). It does raise some questions, for example if you receive disability insurance payments, are they taxable at the federal level? The premiums you paid (SDI) may have been untaxed, partly, or fully taxed depending on how your deduction was figured, and it could change from year to year. For the state, the money used to pay the premiums was always fully taxed.

-Mark Bole