What is the 183Day Rule for California Domicile

It started with a frantic phone call. David, a successful software executive, had moved to Arizona in 2023, believing he’d neatly avoided California state income tax. He’d meticulously tracked his days, spending fewer than 183 in California each year. His mother passed away last month, leaving a beautiful beach house in Laguna Beach, and now his family is facing a potential six-figure tax bill because California is claiming he never truly left. This scenario, sadly, plays out far too often. Clients assume that simply spending less than half the year in the Golden State shields them, and it’s a costly miscalculation.

As an Estate Planning Attorney and CPA with over 35 years of experience, I’ve seen countless estates derailed by these assumptions. The reality is far more complex than a simple day count. While the 183-day rule is a common starting point, it’s a dangerously incomplete understanding of how California determines domicile. It’s not just about where you spend your time, but why and what ties still bind you to the state.

What Actually Determines California Residency?

The California Franchise Tax Board (FTB) doesn’t rely on a rigid 183-day rule. Instead, they employ what’s known as the ‘Closest Connection’ test. This means they evaluate a comprehensive set of 19 factors to determine where your primary domicile truly lies. Simply spending less than 183 days in California does not automatically terminate residency; the FTB uses the ‘Closest Connection’ test (evaluating 19 factors like your primary doctor and social ties) to determine domicile. These factors aren’t weighted equally, and some carry far more significance than others.

• Physical Presence: While not the sole determinant, the number of days you spend in California is still considered.
• Location of Your Home: Where do you consider your principal residence? Where do you direct your mail?
• Driver’s License and Vehicle Registration: These are strong indicators of continued California ties.
• Bank Accounts: Where are the majority of your financial accounts maintained?
• Voter Registration: Are you still registered to vote in California?
• Location of Professional Services: Where do you receive medical and dental care?

The FTB will meticulously examine your life, looking for patterns that reveal your true intent. They aren’t looking for a mathematical calculation; they’re looking for evidence of where you’ve established your permanent home.

How This Impacts Estate Planning

The implications for estate planning are significant. Your domicile at the time of death dictates which state’s laws govern the distribution of your assets and whether your estate will be subject to California’s estate tax (even after the OBBBA Permanent Exemption). Even if you’ve moved out of state, maintaining strong California ties can result in your estate being subject to California probate, which can be a lengthy and expensive process.

The CPA Advantage: Stepping Up Basis & Valuation

As a CPA as well as an attorney, I offer a unique perspective. A proper understanding of domicile is critical for maximizing the step-up in basis of your assets at death. If California is deemed your domicile, the assets will receive a new cost basis equal to their fair market value on the date of death, potentially eliminating significant capital gains taxes when the assets are sold. Accurate valuation, a CPA specialty, is also essential to support that new basis and withstand potential FTB scrutiny.

What About the Small Estate Affidavit and AB 2016?

For real property, it’s crucial to understand the distinctions between different estate administration methods. If the real estate (specifically, a primary residence) is valued under $750,000 for deaths occurring on or after April 1, 2025, the AB 2016 Petition for Succession (Probate Code § 13151) is now available. This requires a Judge’s Order and isn’t simply an affidavit. However, remember that the decedent’s other non-real estate assets typically must remain below the separate $208,850 Small Estate limit to qualify. The Small Estate Affidavit is strictly for real property valued under $69,625, often used for timeshares or vacant land.

• Strong Connection to California: The FTB will use Form 4600 (Residency Questionnaire) to scrutinize your life, including the location of your dentist, the registration of your pets, and where you keep your safe deposit boxes.
• Domicile’s Impact: Your domicile impacts which state’s laws govern asset distribution and potential estate tax liabilities.
• AB 2016 Petition: For primary residences under $750,000 (deaths on/after April 1, 2025), use the AB 2016 Petition, which requires a Judge’s Order.

Don’t make the mistake of assuming a simple day count is enough. A proactive, comprehensive estate plan, informed by a thorough understanding of California residency rules, is the best way to protect your family and ensure your wishes are honored.

How do probate courts in California evaluate intent when a will is challenged?

In California, a last will and testament operates within a probate system that emphasizes intent, clarity, and procedural compliance. When properly drafted, a will does more than distribute property—it creates legally enforceable instructions that guide courts, fiduciaries, and beneficiaries through administration with fewer disputes and less uncertainty.

When a will is drafted with California probate review in mind, it becomes a stabilizing roadmap rather than a source of conflict. Clear intent, proper authority, and compliant execution protect both families and estates.

Controlling Legal Standards for Establishing Domicile and Residency

• Residency Guidelines: FTB Pub 1031 (Guidelines for Determining Resident Status)
  This is the primary resource for the “Closest Connection” test. In 2026, it details how the FTB evaluates 19 factors—including the location of your healthcare providers and social ties—to determine if your presence in the state is “permanent” or merely “transitory.”
• Voter Registration: California Secretary of State – Voter Registration
  Updating your voting address is a critical indicator of intent. For the June 2, 2026, Primary Election, the deadline to register online is May 18, 2026. This serves as a public declaration of your primary home.
• Federal Estate Tax: IRS Estate Tax Overview
  While domicile determines state tax, this resource outlines federal guidelines. It reflects the 2026 OBBBA update, which permanently set the federal estate tax exemption at $15 million per person ($30 million for couples), indexed for inflation.
• Proof of Residency: California DMV – REAL ID Checklist
  Since the federal enforcement deadline passed in 2025, a REAL ID is mandatory for domestic flights. This page lists the specific residency documents (e.g., utility bills, tax returns) that the state accepts as proof of a permanent California address.