Incomplete quarterly estimated payment
I reside in California and I was an employee the first three months of 2023, so my employer was withholding taxes from my paycheck. I retired in April 2023 and I got taxes withheld from my Social Security payments. All the money withheld covers my taxes for 2023, so I didn’t need to do quarterly payments to the IRS.
However, I will start working as an independent consultant in October, so I won’t have taxes withheld from my consultant income. Given that this work opportunity has just happened and was not planned earlier in the year, I couldn’t estimate taxes to do quarterly payments.
1) Should I just make the last 2023 quarter payment in January 2024 to both federal and state?
2) If I do that, could then be penalized because I didn’t do the other three quarterly payments?
3) Also, the 15% self-employment tax is just added to the estimated payments and paid all together, or it is paid separately in a different way?
Thank you for your help