It has only become clear to me recently that I will owe quite a bit more tax for 2019 than what is deducted from my paycheck. (I have sold some mutual fund shares.)
So my intention is to fill out Form 1040-ES for 2019 and use one of the vouchers to send in the estimated additional tax owed. That way I should be able to avoid a penalty and interest.
The question that I have is that the IRS expects quarterly payments when filling out Form 1040-ES. Is it ok if I only use one of the payment vouchers and mail it in to the IRS on or before 01/15/2020?