I searched everywhere and could not find anything that discussed how the two interact. However, now that I am thinking about, perhaps the answer is just by simple analogy to IRS regs. For the IRS, if you pay the entire, let's say, 110%, of last year's tax liability on January 15th fo the following year,the 4th estimated tax deadline, does that mean that there can be no late payment penalty for not paying as you go (on the three prior estimated tax payment dates)? If that answer is "no", that you would need to pay 25% of that safe haven amount by each of the four dates, then presumably the answer for California is that you need to have paid 30% by April 15th, 70% by June 15th, and 100% by January 15th, that is of the safe haven amount (and so would have no penalties regardless of how much higher the tax liability for the later year happened to be)? Does any of what i just argued make sense?
