Proposition 19: Portability For Santa Clara Sellers

Thinking about selling in Santa Clara County but worried you’ll lose your low Prop 13 tax base when you buy again? You’re not alone. Many longtime owners want to right-size, relocate, or move closer to what matters, yet property taxes can feel like the blocker. In this guide, you’ll learn how Proposition 19 portability works, who qualifies, what to expect locally, and the exact steps to claim your benefit in Santa Clara County. Let’s dive in.

Prop 19 portability in a nutshell

Proposition 19 lets eligible homeowners transfer the assessed value of their primary residence to a replacement primary residence anywhere in California. Your new home is then taxed using the transferred base value, not full market value, subject to the program’s rules. The portability provisions took effect for most transfers on April 1, 2021. You can review the full overview on the State Board of Equalization’s Proposition 19 pages for details and examples. See the BOE’s Prop 19 overview.

Who qualifies and key rules

You may qualify if you are age 55 or older, are severely and permanently disabled, or are a victim of a qualifying wildfire or natural disaster. You must have owned the original home and you must occupy the replacement home as your principal residence. If you are 55+ or severely disabled, you can use portability up to three times in your lifetime. Get eligibility guidance from the BOE.

Santa Clara County process, forms, and fee

You file your claim with the Assessor in the county where your replacement home is located. Santa Clara County provides the required forms and a Prop 19 calculator to help estimate outcomes. The county charges a non-refundable $110 processing fee for base-year transfer claims. Start with the local forms and calculator on the Assessor’s site, and contact staff if you have questions. Find Santa Clara’s Prop 19 resources and calculator. For specific BOE forms and local submittal requirements, use the county’s forms page. Access Santa Clara’s forms. For the fee and processing details, review the Assessor’s guidance. See the county’s processing information.

Timing and filing deadlines

You must complete the two transactions within a two-year window. The replacement home can be purchased or built up to two years before or after the sale of your original home, and at least one of the two transactions must occur on or after April 1, 2021. To receive full retroactive relief to the date of change, file the claim within three years of acquiring or completing construction on the replacement home. Review the BOE’s timing rules.

How your new tax base is calculated

If your replacement home’s market value is equal to or less than your original home, your factored base year value transfers without an upward adjustment. If the replacement home is more expensive, the amount above the “equal or lesser” threshold is added to your transferred base value. The rules use 100 percent, 105 percent, or 110 percent thresholds depending on when you buy relative to the sale. For a quick estimate, use the county’s calculator. Try the Santa Clara Prop 19 calculator. For the full methodology and examples, see the BOE’s overview. Learn how values are computed.

Smart planning steps for Santa Clara sellers

• Confirm eligibility. Are you 55+, severely disabled, or a qualifying disaster victim? Check the BOE’s criteria.
• Map your two-year window. Align your sale and purchase dates so they fall within two years, with at least one event on or after April 1, 2021.
• Gather documentation. Keep deeds, closing statements, proof of occupancy, and any age or disability documentation. Use the county’s forms list.
• Run the numbers. Use the local calculator to estimate your new assessed value and potential tax savings. Open the calculator.
• File correctly and on time. Submit the appropriate BOE form to the Assessor in the county of your replacement home, and include the $110 fee if filing in Santa Clara.
• Plan for processing. Claims can take months, and refunds are typically issued after approval.
• Seek counsel for complex cases. Trusts, multi-owner scenarios, and parent-child planning often benefit from legal or tax advice.

Parent to child changes to note

Prop 19 narrowed the former parent-child exclusions. Today, a transfer between parents and children is excluded from reassessment only if the property is a family home or family farm and the child makes it their principal residence. The exclusion is limited by a value test that includes the transferred base value plus an additional statutory amount that the BOE adjusts every two years. Claimants must file for the homeowners’ or disabled veterans’ exemption within one year to qualify. For the current adjustment period, review the BOE’s update. See the BOE’s 2025 adjustment notice.

Cash-flow and escrow expectations

Prop 19 portability is not processed through escrow. You file after both transactions close and after you occupy your replacement home. If you buy first, you may pay full property taxes on the replacement home until your claim is approved, then receive a refund after the Assessor recalculates your bill. Counties reported increased claim volume after Prop 19, which has led to processing backlogs in some areas. Read local reporting on processing trends.

When to get advice

If your situation involves a trust, multiple owners, complex timing, or intergenerational planning, get professional guidance. The Santa Clara County Assessor’s team can answer procedural questions and point you to the correct forms. For market strategy, valuation, and timing your sale and purchase to fit the two-year window, partner with a local advisor who understands Prop 19 and Santa Clara neighborhoods.

Ready to explore your next move with a clear plan for your tax base transfer? Connect with Payne Sharpley to map your sale, estimate your Prop 19 impact, and position your next purchase with confidence.

FAQs

Can my escrow handle my Prop 19 claim?

• No. You must file your claim with the county assessor after closing and after you occupy the replacement home. Escrow typically does not file portability claims. See the BOE’s guidance.

If I buy before I sell, do I lose portability?

• Not if your sale occurs within two years and at least one transaction is on or after April 1, 2021. You may pay full taxes in the interim until your claim is processed. Review timing rules.

How many times can I transfer my base value under Prop 19?

• If you are 55+ or severely and permanently disabled, you can transfer up to three times. Check eligibility details.

Does Prop 19 affect my federal capital gains taxes when I sell?

• No. Prop 19 only affects California property tax assessed value. Federal capital gains rules are separate, so consult your tax advisor. See BOE context.