According to IRS Publication, https://www.irs.gov/businesses/small-businesses-self-employed/estimated-taxes, "Individuals, including sole proprietors, partners, and S corporation shareholders, generally have to make estimated tax payments if they expect to owe tax of $1,000 or more when their return is filed.
Corporations generally have to make estimated tax payments if they expect to owe tax of $500 or more when their return is filed.
You may have to pay estimated tax for the current year if your tax was more than zero in the prior year."
With all that being said, you are not required to make these payments.
These are generated for your convenience and nothing is transmitted to the
IRS.
If
you did owe more than $1000 in 2017 and your tax situation will be the same
next year, the IRS recommends paying estimated taxes to avoid an underpayment
penalty next year.