January 15, 2016 is the final deadline for making estimated tax payments for the year 2015.IRS
Who Must Pay Estimated Tax

If you are filing as a sole proprietor, partner, S corporation shareholder, and/or a self-employed individual, you generally have to make estimated tax payments if you expect to owe tax of $1,000 or more when you file your return.

If you are filing as a corporation you generally have to make estimated tax payments for your corporation if you expect it to owe tax of $500 or more when you file its return.
If you had a tax liability for the prior year, you may have to pay estimated tax for the current year. IRS