Unincorporated-Area Address Changes

Q: My Place Name has changed - does this mean I now live in a different city?
A: No, if your Place Name has changed, you do not live in a different City. This change only impacts addresses in unincorporated Alameda County - by definition, these addresses are not in a city. This Place Name does not change jurisdictional boundaries (i.e. where you live)- it simply replaces the default Place Name used by USPS so that it matches the official names of the county's unincorporated communities.

Q: Can I still use my old Place Name?
A: Yes! Your unincorporated community name is now the default on USPS.com, but USPS will continue to accept mail with the old Place Name as long as you include the correct street name and ZIP Code.

Q: Is my old Place Name no longer recognized?
A: USPS will continue to recognize old Place Names as optional alternatives to official unincorporated community Place Names. See USPS's Cities by ZIP Code look up tool.

Q: What happened to "unincorporated Hayward" and "unincorporated San Leandro"?
A: "Unincorporated Hayward" and "unincorporated San Leandro" are informal terms that have been used over time to refer to the county's unincorporated communities, but these have never been their official names. These communities have their own names - Ashland, Cherryland, Hayward Acres, Fairview, San Lorenzo, and Castro Valley - which have been recognized in the County's General Plan since the 1960s or earlier. Hayward and San Leandro are incorporated cities, and are separate and distinct from the unincorporated communities.

Q: Has my ZIP Code changed?
A: No, this change does not impact ZIP Codes.

Q: Which addresses were impacted by the Place Name updates?
A: This project updated approximately 29,000 addresses in the unincorporated communities of Ashland, Cherryland, Hayward Acres, Fairview, San Lorenzo, and Castro Valley with ZIP Codes of 94578, 94580, 94541, 94542, 94552, and 94546. Because Castro Valley and San Lorenzo have their own Post Office branches, many addresses in Castro Valley and San Lorenzo already had current Place Names and were not affected.

Q: How does this impact mail delivery to my house?
A: This change does not impact mail delivery to your house because your ZIP Code remains the same.

Q: Will my postal delivery person remain the same?
A: This change does not impact mail routes and will not impact USPS staffing assignments.

Q: If I need to pick up a package at the Post Office, which one do I go to now?
A: Your mail will continue to be delivered by the USPS Branch associated with your ZIP Code, which has not changed. If you need to pick up a package from the post office, you will continue to go to the USPS Branch associated with your ZIP Code.

Q: Do I need to inform anyone about my address change?
A: This is optional for you. While unincorporated Community Names are now the default USPS Place Names , USPS will continue to accept and deliver mail with an old Place Name as long as you include the correct street address and ZIP Code.

Q: Do I need to change my address everywhere? For example, with my bank, my utility companies, etc.?
A: This is optional for you. It will take time before the updated USPS Place Names are universally reflected in address verification systems used by banks, utility companies, and other service providers, which may use third-party address vendors and databases that are not directly connected to USPS records. You can choose to change your address with your service providers at your discretion, as their systems allow. Inconsistencies in USPS Place Names will not impact mail delivery as long as residents continue use the correct street address and ZIP Code.

Q: Can I continue to use address labels with my old Place Name?
A: Yes. While unincorporated Community Names are now the default Place Names with USPS, USPS will continue to accept and deliver mail with your old Place Name as long as you include the correct street address and ZIP Code.

Q: Does this impact my tax rate?
A: No. You will continue to be taxed as a resident of unincorporated Alameda County. You can look up your sales tax rate by address on the California Department of Tax and Fee Administration's website. The Alameda County Assessor's office determines property tax rates based on jurisdictional boundaries, which are unaffected by this change.

Q: How does this impact my property records, i.e. County tax records, property deeds, County building files, and other County records?
A: Assessor parcel numbers ("APNs"), not addresses, are the unique identifier that the County Assessor assigns to pieces of property for assessment and record-keeping purposes. The Place Name change does not impact APNs. You can look up your APN here. The County Assessor's office is in the process of updating its address records for consistency with the updated Place Names. This may take some time. The updated addresses will not have any impact on tax rates because it does not involve a change of jurisdiction and does not change your APN. Inconsistencies in "city" names in County databases do not affect the validity of assessments, property taxes, or property records.

Q: Am I now in a different school district?
A: No, this change does not impact school district boundaries.

Q: Does this impact who I call for essential services, like public safety, fire, sewer, and water?
A: No, service provider and special district boundaries are not impacted by this change. To learn more about services and other aspects of civic life in unincorporated Alameda County, visit https://www.alamedacountyca.gov/uninc/.

Q: How was the community involved in the decision to make this change?
A: This change is the result of a long-term effort of the Eden Area Livability Initiative, a community-driven effort launched in December 2004 by Alameda County to improve the quality of life in the unincorporated Eden Area of Alameda County. With direction from Supervisor Nate Miley of District 4 and Supervisor Lena Tam of District 3, CDA staff conducted a community survey and presented at 8 public meetings in 2023 prior to bringing recommendations to the Board of Supervisors. A summary of the 2023 outreach activities is archived here.

Q: When will my updated USPS Place Name show up in online mapping applications, private business address verification systems, and elsewhere outside the USPS databases?
A: It will take time before the USPS Place Name address changes are universally reflected in mapping applications, address verification systems, and elsewhere outside the USPS and County databases. While USPS is the official source for mailing address data, agencies and private companies acquire address data updates through a variety of sources, including through third-party address vendors and services. Residents will notice inconsistencies across various platforms until these decentralized systems catch up to the changes. Inconsistencies in USPS Place Names will not impact mail delivery as long as residents continue use their street address and ZIP Code.

Q: I'm getting a new driver's license or registering a vehicle, and my updated Place Name isn't an option in the DMV database. When will the DMV recognize the Place Name update?
A: The County is working with State Assemblymember Liz Ortega's office to communicate the Place Name updates to the State and the DMV. This may take some time. If you are waiting for an official DMV document to arrive in the mail, USPS will deliver mail with your old Place Name or new Place Name as long they have your correct street address and ZIP Code.

Q: Do I need to change my address on my passport?
A: Addresses are not printed on US Passports. Per the US State Department's website, "You don't need to update your current passport with your new address." If you have a passport application in process and are waiting for your passport to be delivered, USPS will deliver mail with your old Place Name or new Place Name as long they have your street address and ZIP Code.

Q: Where can I find documentation about my new official USPS Place Name?
A: The USPS address lookup tool shows the updated default Place Name for all addresses in urban unincorporated Alameda County. Type in your address, state, and ZIP Code, and the tool will return your current default USPS Place name.

Q: How is the County communicating these changes to the community?
A: The County launched an outreach campaign beginning in April 2025 to inform the public about the USPS Place Name changes. The multimedia outreach campaign includes social media posts, billboard announcements, traditional press releases, grassroots outreach via community partners, and postcards mailed to affected addresses.

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