Taxpayers with refunds coming can file late without penalties as long as they don't miss it by too much. There is one catch: Neither the Feds nor the State of CA allow you to file electronically after the extension deadline—you have to apply postage and mail it in. This delays your refund, of course, but you will still get it. I know this first hand.
If you owe 2022 taxes, the payment deadline was April 18, 2022 even if you filed an extension. The Federal extension was October 16, 2023. California moved their filing deadline to November 16, 2023.
Turbotax has never calculated the late payment fine correctly but it isn't all that big and depends on when you actually file past the April date and how much you still owe. Don't worry, both the Fed and State will send you a bill if you didn't pay enough. Again, I know this first hand.
Of course, you can use TurboTax to amend your returns up to the time the law allows (3 years, last I checked but I could be wrong). Again, you will need to put postage on it and send it via the mail.
