It depends on what TurboTax product you are using. If you have a Desktop product which you are using to prepare both your and your partner's returns, and his has a California return that is not correct / not needed, check the Personal Info section to be sure there is no reference to California in any of the responses.
Follow these steps to delete a state return in TurboTax Desktop for Windows:
- With your return open in TurboTax, from the File menu, choose Remove State Return.
- Select the return you want to delete and then select Remove.
- Choose Yes to confirm.
If you are in TurboTax Online, you need a different account for each individual's return. That product is designed to prepare one individual's Federal and State returns.