I am calculating the possible underpayment for 2019. I got paid from my employer evenly throughout 2019, and each quarter I also made estimate the tax payment though I paid the estimated tax a little more in Q4 compared with other 3 quarters. Question is, can I choose between the annualized installment method and regular method freely and choose which ever method favors me even if I was paid evenly, the income tax was evenly withheld, but I paid more estimate tax in the later part of the year?