Connecticut Quarterly Estimated Tax Payments for LLCs

Connecticut LLC members must make quarterly estimated payments if expecting to owe $1,000+ in CT income tax. Without employer withholding on LLC income, these payments prevent underpayment penalties. For the full tax picture, see our tax guide. For formation, see our LLC guide.

When Required

CT estimated payments required if expecting $1,000+ in CT income tax after withholding and credits.

Due Dates

How to Pay

• Online: myconneCT (Connecticut's tax portal) at portal.ct.gov/DRS
• Mail: CT-1040ES vouchers to Department of Revenue Services

Safe Harbor

• Pay 100% of prior year's CT tax in four equal installments
• Or pay 90% of current year's liability
• Connecticut's threshold: $1,000 (same as federal)

PET Estimated Payments

If your LLC elects the pass-through entity tax (PET), entity-level estimated payments may also be required — separate from individual member estimates. Check DRS guidance for the current PET estimated payment schedule.

FAQ

Do I also make federal estimated payments?

Yes. Federal ($1,000 threshold) and Connecticut ($1,000 threshold) estimated payments are separate obligations to separate agencies. Make both quarterly.

What's the CT underpayment penalty?

Interest on each underpaid quarter at DRS's published rate (typically 7-10%). Using the safe harbor (100% of prior year tax) avoids all penalties.