Form CT-1040X - Amended Connecticut Income Tax Return

Form CT-1040X is the official document used to amend your previously filed Connecticut (CT) income tax return. This allows you to correct errors, report additional income, or claim deductions or credits you missed on your original filing.

When to File Form CT-1040X?

A. You discovered an error: This could be a miscalculation, inaccurate reporting of income or deductions, or missing information.

B. You need to report additional income: This might include income received after originally filing your return, such as late-reported wages or interest income.

C. You have new deductions or credits to claim: This could involve deductions you weren't aware of at the time of filing or credits you became eligible for later.

D. The IRS or federal courts amended your federal return: If changes to your federal return affect your CT tax liability, use Form CT-1040X to adjust your CT return accordingly.

What You Can't Change with Form CT-1040X?

  1. You cannot change your filing status (e.g., single to married) or your method of accounting (e.g., cash to accrual).
  2. You cannot use it to make estimated tax payments or change contributions to designated charities.

Filing Instructions for Form CT-1040X:

Step 1: Download the latest version of Form CT-1040X attached below.

Step 2: Complete the form accurately and follow the instructions provided.

Step 3: Attach any necessary supporting documentation to your amended return.

Step 4: Mail your completed form and any attachments to the DRS address specified on the form.

Form CT-1040X Deadline:

Generally, you have 3 years from the original due date of your tax return (including extensions) to file Form CT-1040X. However, specific exceptions may apply. It's recommended to consult the DRS website or a tax professional for the most up-to-date deadlines.