if your adjusted gross income for 2022 was over $150,000, then the safe harbor is that 110% of your 2022 tax, otherwise it's 100%, must be paid in through withholding and estimated tax payments. Generally, the law requires that 1/4 of this number be paid in each quarter 4/15/,6/15,9/15 1/15 of following year. if not, then to avoid or reduce penalties for underpayment in the earlier quarters you must compute your taxes for each quarter using the annualized income installment method. see form 2210 page 3. https://www.irs.gov/pub/irs-pdf/f2210.pdf the law gives you the option of treating withholding as if 1/4 was paid in for each quarter regardless of when actually withheld. there is also the option to use the actual amount withheld in each quarter.
"Also, saw something that we don't need to make Q4 estimated in Jan if we pay taxes on time in April. Is that right" No to skip the 1/15 estimate the return must be filed and balance paid by 1/31/2024
