State tax filing
It depends. As a nonresident of California, you would only have to pay income tax for income that is California sourced. Sourced income includes income from performing services in California. It would not include services performed in Texas for a California based company.
In addition, per the FTB, you will only need to file a nonresident return if you have sourced income in the state and your California income is above a certain amount. I have attached the income guidelines below.
If your sourced income for 30 days is above the amounts for your filing status, then you would have to file a nonresident return. If not, then generally, you would not have to file. If you do not have a filing requirement, then I would advise not to continue to withhold California income taxes from your pay when you are a Texas resident.
For more information, please see 2020 540NR.
