US state guide

Connecticut CT-W4 withholding code explained

Connecticut is different from a flat-rate state because the employee's withholding code changes the annualised calculation path.

In short

Connecticut uses withholding codes A, B, C, D and F rather than a simple one-size-fits-all state rate. The code affects the personal exemption, the initial tax calculation, phase-out add-backs and personal tax credits.

What the code changes

Code A, B, C and F each have different exemption thresholds and tax tables. Code D is special because the personal exemption and personal tax credit are both zero in the worksheet method used by the calculator.

Why the estimate may still differ from a pay stub

Connecticut withholding can also be adjusted by line 2 extra withholding and line 3 reduced withholding on Form CT-W4. Supplemental compensation can follow separate rules too, so a salary estimate is not the same thing as a full payroll record.

How to get a closer match

  1. Choose the code from your CT-W4.
  2. Check whether you asked for extra withholding or reduced withholding.
  3. Compare the annual estimate with a recent payslip.

Use the US take-home pay calculator for the annual estimate. This guide is a plain-English summary only.