Every employer with an office or business presence in Connecticut must withhold state income tax from wages paid to resident and nonresident employees for each payroll period, with the amount calculated to approximate each employee’s annual Connecticut tax liability as closely as possible. Meeting Connecticut’s withholding tax requirements for employers means registering with the Department of Revenue Services, collecting a CT-W4 from every worker, using the current DRS tables or calculation rules to compute the withholding, depositing electronically on your assigned schedule, and filing quarterly and annual reconciliations on time. Miss any of those steps and you face a 10% penalty, 1% monthly interest, and possible personal liability under Section 12-736.
Register With DRS Before Your First Payroll
New businesses register through the myconneCT portal to open a withholding tax account. If you’re already registered with DRS for other state taxes, you use the same portal to add withholding as an additional tax type.1Connecticut State Department of Revenue Services. New Employer Information Unemployment taxes are handled separately through the Connecticut Department of Labor, so plan on that registration as well.
Collect a CT-W4 From Every Employee
Section 12-705 of the Connecticut General Statutes requires withholding from wages paid to both resident and nonresident employees working in the state.2Justia. Connecticut Code Title 12 Taxation Chapter 229 Sec 12-705 – Withholding of Taxes From Wages and Other Payments Form CT-W4 tells you the employee’s filing status and the information needed to compute the right amount. Employees can update the form at any time.
If an employee never turns in a CT-W4, you don’t get to estimate. Connecticut requires you to withhold at the state’s highest marginal rate of 6.99% with no exemption allowance.3Connecticut Department of Revenue Services. Form CT-W4 Employee’s Withholding Certificate That’s a strong reason to follow up with anyone who hasn’t submitted the form.
Calculate Withholding Using DRS Tables or TPG-211
Connecticut gives you two options: the annual withholding tables or the withholding calculation rules published in TPG-211. There is no percentage method for Connecticut withholding, so a flat percentage of wages isn’t a valid shortcut.4Connecticut Department of Revenue Services (DRS). TPG-211, 2025 Withholding Calculation Rules
The DRS updates both the tables and the calculation rules regularly. The 2026 withholding tables took effect January 1, 2026.5Connecticut Department of Revenue Services. State of Connecticut 2026 Withholding Tables If you run payroll manually, work from the current year’s version. Using last year’s tables is one of the more common errors DRS sees.
Bonuses, Commissions, and Other Supplemental Wages
Connecticut withholding is not required on compensation that is exempt from federal income tax withholding. For supplemental wages that are subject to withholding, follow the DRS calculation rules to determine the state amount. State and federal calculations run independently, so complete both.
Deposit, File, and Reconcile on Schedule
DRS assigns employers to a weekly, monthly, or quarterly deposit schedule based on payroll size. All withholding tax payments must be made electronically through myconneCT.6Connecticut State Department of Revenue Services. 2026 – Withholding Tax Information
Regardless of deposit frequency, every employer files Form CT-941, the Connecticut Quarterly Reconciliation of Withholding, for each calendar quarter. These are due by the last day of the month following the quarter’s close: April 30, July 31, October 31, and January 31.7Cornell Law School. Conn. Agencies Regs. 12-707-1 – Schedule for Filing Withholding Tax Returns and Payment of Taxes
By January 31 each year, provide every employee a W-2 showing total wages paid and taxes withheld for the prior calendar year, and file copies of all W-2s with DRS along with Form CT-W3, the annual reconciliation. Connecticut requires W-2 filings for all employees who received Connecticut wages, even when no state income tax was actually withheld.8Connecticut State Department of Revenue Services. Form W-2 Electronic Filing Requirements
Report New Hires Within 20 Days
Every newly hired employee must be reported to Connecticut’s Directory of New Hires within 20 days of the hire date. Employers who report electronically may instead submit two monthly transmissions no less than 12 and no more than 16 days apart.9Office of the Law Revision Counsel. 42 USC 653a – State Directory of New Hires The report includes the employee’s name, address, and Social Security number, plus your business name, address, federal tax identification number, and state tax identification number.
Handle Multi-State and Remote Workers Carefully
Connecticut has no reciprocal income tax agreements with any other state, including New York, Massachusetts, and Rhode Island.10Connecticut General Assembly. State Income Taxes on Income Sourced to Other States A nonresident working in Connecticut generally owes Connecticut tax on wages earned here and may also owe tax in a home state, though most states offer a credit for taxes paid to another state.
Connecticut applies a “convenience of the employer” rule, but only on a reciprocal basis. If a nonresident employee of a Connecticut-based employer works remotely from a state that itself imposes a convenience rule, such as New York, Connecticut sources those wages to Connecticut unless the remote arrangement exists because of the employer’s necessity rather than the employee’s preference.11Connecticut General Assembly. Convenience of the Employer Rule The rule does not apply to employees living in states without a similar framework.
Whenever you hire someone who lives out of state, or when an existing employee moves across state lines, review your withholding obligations in both states before the next payroll runs.
Exemptions Employees Can Claim
An employee who expects combined annual gross income of $24,000 or less can request exemption by completing the appropriate section of the CT-W4.3Connecticut Department of Revenue Services. Form CT-W4 Employee’s Withholding Certificate Military spouses may claim an exemption under the federal Military Spouses Residency Relief Act on the same form.
You don’t have to independently verify that an employee actually qualifies, but you do need the completed CT-W4 on file. If DRS later determines the exemption was improperly claimed, the tax liability falls on the employee, though accepting a clearly invalid form can still draw questions.
Keep Records for at Least Four Years
Connecticut regulations require employers to maintain all records necessary to determine correct tax liability, including CT-W4 forms, payroll records, and records of amounts withheld and remitted. These records must be kept for at least three years from the extended due date of the return and produced on request.12Connecticut eRegulations. Sec. 12-2-12 – Recordkeeping and Record Retention
The IRS requires employment tax records to be kept for at least four years after filing the fourth quarter return for the year.13Internal Revenue Service. Employment Tax Recordkeeping Since you have to satisfy both, four years is the safer floor.
Penalties for Getting It Wrong
The penalty structure sits in Section 12-735 of the General Statutes, and the numbers compound quickly.
Late Payment
Failing to pay the tax reported on your return by the due date triggers a penalty of 10% of the unpaid amount, plus interest at 1% per month or any fraction of a month from the original due date until payment.14FindLaw. Connecticut General Statutes Title 12 Taxation 12-735 – Failure to Pay Tax or Make Return On a $10,000 shortfall that’s $1,000 on day one and $100 every month afterward.
Failure to File
If you don’t file a required withholding return within three months of the deadline, the DRS Commissioner may prepare one on your behalf using the best available information. The penalty is 10% of the tax or $50, whichever is greater, plus the same 1% monthly interest.14FindLaw. Connecticut General Statutes Title 12 Taxation 12-735 – Failure to Pay Tax or Make Return
Personal Liability
Under Section 12-736, DRS may assess any person responsible for collecting, accounting for, or remitting withholding taxes a penalty equal to the full amount of tax evaded, not collected, or not paid over.15Connecticut State Department of Revenue Services. Can I Be Held Personally Liable for Payment of Business Taxes Officers, directors, and anyone with authority over company finances can be assessed personally, on top of any criminal penalties that may apply.
The federal counterpart is the IRS Trust Fund Recovery Penalty. It reaches any responsible person who willfully fails to collect or pay employment taxes, and the IRS treats “willful” broadly: knowing taxes were owed and paying other creditors instead qualifies.16Internal Revenue Service. Employment Taxes and the Trust Fund Recovery Penalty (TFRP)
Requesting a Waiver or Filing an Appeal
If a penalty resulted from circumstances beyond your control rather than neglect or intentional disregard, you can ask DRS for a waiver on reasonable-cause grounds. Submit Form DRS-PW through myconneCT, by fax, or by mail.17Connecticut State Department of Revenue Services. Penalty Waiver Request, Offer in Compromise or Protest A few conditions apply. You must pay all tax and interest first; interest itself cannot be waived. Waivers aren’t available for audit-generated penalties or for certain penalties excluded by DRS policy.
To contest an assessment rather than seek a waiver, file a formal protest with DRS within 60 days of the date on the notice. DRS reviews the protest internally and may hold a hearing. If you disagree with the DRS decision, you have one month from that decision to appeal to the Connecticut Superior Court in the New Britain Judicial District.18Connecticut General Assembly. Tax Appeal Process Complete payroll records, CT-W4 forms, and deposit histories are what employers rely on to show good faith at every stage.