I received a State Income Tax Balance Due Notice from CA FTB and I wonder what is this about? I used TurboTax and I need assistance to figure this out!

When you prepared your state return, did the tax form show that you owed a balance due to the state?   If so, how did you pay your state tax?   Did you mail the state a check or money order?   Did you pay the state on the state's web site?

Or...did the state change something on your return that is resulting in an amount that you now owe?   What does the letter from the state say?   

TurboTax gets no information from the state after you file your return, so no one at TT knows why you owe the state.

Check your California state form 540 line 111 to see if you had a tax due.

Your only proof of payment is your bank statement or credit card showing the payment coming out. Turbo Tax only passes your bank account number to the state for the state to take it out of your account. But most states do not let you pay by Direct Debit so you have to mail in a check or go directly to the state's website to pay. And better double check your bank account and routing number with your bank. Some banks use a different routing number for deposits and payments.

Check the printout or PDF of your return; look for the state cover sheet with the Turbo Tax logo. If you owed tax, it will show the payment information and how/when you decided to pay. Read the state payment instructions carefully since most states cannot be paid from within the TT system and requires additional steps.