A local tax expert says mark Jan. 15 on your calendar.
Roy Abramowitz, of New Canaan, says if you do not pay your final 2025 estimated taxes by that date, you could owe the IRS penalties and interest.
He also warns that going on extension April 15 does not delay payment.
It is an extension of time to file, not an extension of time to pay.
If you do not pay by April 15, your tax return extension will be invalid.
Abramowitz says you could also owe interest, underpayment and late filing penalties.