A Guide to Filing Connecticut State Tax as a US Expat

Federal taxes are an obligation for all Americans, regardless of where they live, but what about state taxes? For Connecticut residents, the answer depends on whether you’ve fully cut ties with the state. If you keep a home, financial accounts, or strong connections in Connecticut, you may still be considered a resident for tax purposes and be required to file a state return.

If you’re a former resident of Connecticut living abroad, here’s what you need to know about your state tax obligations.

Understanding Residency Rules in Connecticut

Connecticut determines residency for tax purposes based on both where you live and where your income comes from. The state recognizes three types of residency: full-year resident, part-year resident, and nonresident. Each status affects how your income is taxed, making it important to know which one applies to you.

Domicile Rules for Connecticut Residents Abroad

Beyond your physical presence in Connecticut, residency is also determined by whether the state considers you domiciled there. Domicile refers to your permanent legal home, the place you intend to return to. Even if you spend years abroad, Connecticut may still treat you as domiciled if you maintain strong ties to the state, such as:

• Driver’s license
• Voter registration
• Property ownership
• Mailing address and banking ties

To truly end your state residency in Connecticut, you generally need to cut these ties. If you don’t, the state may continue to tax you as a full-year resident. However, on the other hand, just having a driver’s license alone doesn’t mean you are domiciled; it’s based on where you are seen as having your permanent home.

Do You Need to File a State Return in Connecticut as an Expat?

Once you understand your residency status, you will be able to determine whether or not you need to file a Connecticut return while living abroad:

Full-Year Residents

If Connecticut still considers you a full-year resident (for example, because of domicile ties like a home, driver’s license, or voter registration), or if you maintain a permanent place of abode in Connecticut and spend more than 183 days there, you must file a Connecticut return. Full-year residents are taxed on all worldwide income.

Part-Year Residents

If you moved into or out of Connecticut during the year, you’ll need to file a Connecticut return. The state taxes your worldwide income during the months you lived in Connecticut, plus any Connecticut-sourced income for the rest of the year.

Nonresidents

If you’re classified as a nonresident, meaning you’ve cut Connecticut domicile ties, don’t maintain a permanent home in the state, and spent fewer than 183 days there, you only need to file if you have Connecticut-sourced income. Common examples include remote work performed for a Connecticut employer, rental income from Connecticut property, or business income sourced in the state.

The table below summarizes Connecticut’s residency classifications and how each status is taxed.

Learn more at the Connecticut Department of Revenue Services.

Does Connecticut Have a State Income Tax?

Yes, Connecticut income tax rates are progressive, with seven brackets ranging from 2% to 6.99%. The higher your income, the higher the percentage you’ll pay. For the 2024 tax year, here are the basic brackets:

Note: Tax rate thresholds vary by filing status (e.g., married filing jointly or head of household), however, the rates themselves are the same. For full details, see the official Connecticut Tax Calculation Schedule (CT-1040 TCS 2024)

How Connecticut Treats Foreign Income, Exclusions, and Tax Credits

When you file your federal return as a US expat, you may be able to use the Foreign Tax Credit (FTC), the Foreign Earned Income Exclusion (FEIE), or housing deductions to reduce or eliminate double taxation. Connecticut, however, does not follow these federal provisions.

If you are considered a full-year or part-year resident, your worldwide income is taxable at the state level. You cannot exclude foreign earned income, deduct foreign housing expenses, or claim credits for foreign taxes paid. The only credit Connecticut allows is for taxes paid to another US state on the same income. That means your income could end up being taxed twice, once by the country where you live and again by Connecticut.

Other Considerations

Connecticut also taxes common types of income at the same progressive rates as wages, including:

• Rental income from property (whether in Connecticut or abroad).
• Capital gains and investment income.
• Retirement income (pensions, IRAs, Social Security), some exemptions apply depending on your Adjusted Gross Income (AGI). For example, certain pensions (military or public service) may be fully exempt.

Connecticut State-Specific Forms You May Need

Just like you file Form 1040 at the federal level, Connecticut has its own state tax return forms:

• Form CT-1040: For full-year residents
• Form CT-1040NR/PY: For nonresidents and part-year residents

Using the correct form based on your residency status ensures you file accurately and avoid processing delays.

Connecticut State Tax Filing Deadlines and Extensions

Connecticut state taxes are due April 15, the same date as your federal return. If you need more time, you can request an extension until October 15 by filing Form CT-1040EXT. Keep in mind that an extension only applies to filing, not payment. Any state taxes owed must still be made by April 15 to avoid accruing interest and penalties.

For full details, see the Connecticut DRS guidance on extension for Americans living abroad.

Penalties for Not Filing

Failing to file Connecticut state taxes can result in avoidable penalties, interest charges, and even audits. The Connecticut Department of Revenue Services (DRS) enforces these rules even if you’re living abroad, and they can legally pursue you for unpaid taxes. You can review the full penalty and interest details on the Connecticut DRS website.

How to Sever Ties with Connecticut and Avoid Future Tax Liabilities

If you’ve moved abroad and want to ensure Connecticut no longer considers you a resident for tax purposes, you must demonstrate that you’ve severed your ties with the state. Connecticut taxes full-year residents on worldwide income, so unless you take steps to end residency, the state may continue to treat you as domiciled.

Steps to Sever Residency:

• Surrender your Connecticut driver’s license (and obtain a new one in your new country of residence, if possible).
• Sell or lease out any property in Connecticut so you no longer maintain a permanent home there.
• Move your banking and mailing address abroad to show a permanent shift in your financial and personal connections.

Establishing Foreign Residency:

It’s not enough just to leave the state; you must also prove you’ve established residency elsewhere. Showing ties such as foreign property, local bank accounts, and residency permits strengthens your case and helps prevent Connecticut from classifying you as a resident for tax purposes.

States Without Income Taxes

Some states don’t impose an income tax at all. If you’re domiciled in one of these states, you typically won’t have to file a state return while living abroad:

• Alaska
• Florida
• Nevada
• South Dakota
• Tennessee
• Texas
• Wyoming
• New Hampshire (as of January 1, 2025, when its Interest & Dividends Tax is fully repealed)

For expats, this can simplify things significantly. However, if you maintain ties to states that do impose an income tax, like California, New York, or Connecticut, you could still be required to file and pay state taxes even while abroad.

Always confirm with your state’s Department of Revenue before assuming you’re exempt.

File It All at Once With MyExpatTaxes

Filing from abroad can feel overwhelming when you’re juggling both federal and state requirements. Connecticut, in particular, can be strict about enforcing residency rules and worldwide income reporting, which means expats can’t afford to miss deadlines. With MyExpatTaxes, you don’t have to juggle separate filings. Our software makes it simple to file your federal and state returns together in one streamlined process.

Whether you’re still considered a Connecticut resident, moved out mid-year, or need to prove nonresident status, MyExpatTaxes helps ensure every detail is handled correctly. And if your situation is more complex, our tax professionals are available to guide you through the rules so you can file with confidence.

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