I filed married-joint last year, but will be filing married-separate this year. I will owe more tax than what will be withheld. How can I pay off this difference?

[vabhijit]

In 2019, I filed "married-joint". This year, it will be "married-separate". I changed my withholding in March 2020, but see that I will still owe more tax than what will be withheld, at the end of the calendar year. For last year too, I had to make a tax payment as I owed IRS money (already taken care of)

Do I need to avoid owing taxes going into April, to avoid interest charges? What is the best way to pay off the extra amount that I owe, ahead of April 2021?

[Critter-3]

You have 2 options ...

1) increase your withholdings at your job for the rest of the year ...  fill in a new W-4 and put an amount on line 4     https://www.irs.gov/pub/irs-pdf/fw4.pdf

2) make an estimated payment 

How do I make estimated tax payments?

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