Your next chapter.
Our platinum standard.
From personal tax returns to the everyday needs of your business, get support that starts with understanding you.
Serving individuals, businesses and nonprofit organizations.
A personal approach.
A professional standard.
Tax service, bookkeeping and payroll
in Maywood, California.
Celebrating 40 years of service.
For 40 years, Castellanos Platinum Tax Service has served individuals, families, businesses and nonprofit organizations with tax and business support. Our work begins with listening, understanding your needs and helping you take the next step with clarity.
Today, we bring that commitment to personal, corporate and nonprofit tax services, bookkeeping, payroll, and corporation formation and compliance.
Professional care.
Personal attention.
Our mission is to provide accurate, dependable tax and business services with integrity, clear communication and personal attention—helping every client understand their responsibilities and make informed decisions with confidence.
Six services.
One team to turn to.
Choose the service that fits your needs, then speak with our team about your next step.
Personal taxes
Preparation support for individuals and families, with a clear review of your income documents and filing needs.
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Corporate taxes
Tax preparation for corporations, with attention to the records and filing needs of your business.
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Nonprofit taxes
Tax preparation support for nonprofit organizations. Contact our team to discuss your organization and its filing requirements.
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Bookkeeping
Keep income, expenses and business records organized with bookkeeping support tailored to your needs.
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Payroll
Talk with our team about payroll support and the needs of your business.
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Corporation Formation & Compliance
Support for corporation formation and ongoing compliance. Contact our team to discuss starting your corporation or keeping an existing corporation organized.
Explore service ↗Start with a conversation.
Tell us what you need.
Call our office to discuss your personal, business or nonprofit needs and arrange an appointment.
Bring the right records.
We will help you identify the documents to gather for your service and situation.
Understand your next steps.
Review the details with our team and ask questions before moving forward.
The people behind your platinum service.
Administrative Back Office
Veronica Sanchez
Thasha Washington
Alma Sanchez
Front Office Support
Yecel Vasquez
Gracie Vasquez
CTEC Registered Tax Preparers
Tax Preparers
Our tax preparation team brings a professional, client-focused approach to every return. We take time to understand your circumstances, review supporting records carefully, and explain the filing process in clear language. With an emphasis on accuracy, integrity, and personal attention, we help individuals, families, and business owners prepare their tax information and approach their next steps with confidence.
Fernando Castellanos
Anthony Corona
MPA, ERO
John Castellanos
Sergio Castellanos
Isabel Alvarez
Manny Arana
Sandra Sanchez
Salvador Castellanos
Your tax deadline calendar.
2026 tax-year returns · filed in 2027. Standard calendar-year planning dates calculated from current agency rules. Check for later updates before filing.
Request a federal extension by the original return due date: Form 4868 for individuals or Form 7004 for eligible businesses. California generally provides an automatic filing extension subject to its rules. Pay balances by the applicable original payment deadline.
When must I request an extension?
March 15, 2027: Federal requests for calendar-year S corporations and LLCs taxed as partnerships (Form 7004).
April 15, 2027: Federal requests for individuals (Form 4868), individual-owned disregarded LLCs with the owner’s return, and calendar-year C corporations (Form 7004).
California: A separate extension application is generally not required for eligible taxpayers. The automatic filing extension does not postpone tax payments. Confirm eligibility and account standing with our office.
| Taxpayer | Common returns | Original filing deadline | Federal extension request due | Federal extended filing | California extended filing |
|---|---|---|---|---|---|
| Personal / individual | 1040 / CA 540 | Apr 15, 2027 | Apr 15, 2027 Form 4868 | Oct 15, 2027 | Oct 15, 2027 |
| C corporation | 1120 / CA 100 | Apr 15, 2027 | Apr 15, 2027 Form 7004 | Oct 15, 2027 | Nov 15, 2027 |
| S corporation | 1120-S / CA 100S | Mar 15, 2027 | Mar 15, 2027 Form 7004 | Sep 15, 2027 | Sep 15, 2027 |
| LLC taxed as a partnership | 1065 / CA 568 | Mar 15, 2027 | Mar 15, 2027 Form 7004 | Sep 15, 2027 | Oct 15, 2027 |
| Single-member LLC owned by an individual, disregarded for tax | Owner’s federal return / CA 568 | Apr 15, 2027 | Apr 15, 2027 Form 4868 | Oct 15, 2027 | Oct 15, 2027 |
LLC classification matters: An LLC taxed as an S or C corporation follows the corporation category. Other single-member LLC ownership arrangements can have different California dates; ask our team to confirm your category.
Separate payment schedules: Estimated taxes, California LLC annual tax and fees, and payroll taxes have their own due dates and are not postponed by a return filing extension.
Calendar-year returns only. Fiscal years, short years, overseas taxpayers, disaster relief, and other special rules may change the dates. This is a planning calendar, not a personalized filing determination. Reviewed October 14, 2026.
Save dates to your calendar Confirm your deadlineOfficial dates and extension resources
IRS personal extensions ↗ · IRS business extensions ↗
California business deadlines ↗ · California extensions ↗
Let's talk about
what comes next.
Whether you're preparing a return or looking for ongoing business support, contact our Maywood office.
6033 Atlantic Blvd #7
Maywood, CA 90270
Hours of Operation
Call our office Monday–Thursday, 10:00 a.m.–4:00 p.m.
Closed holidays.
Tax Season: January 15–April 15
Open 7 days a week. Call for tax-season hours and appointment availability.
Keep us in your contacts.
Scan to save our phone, office address and website. On this phone? Use the button below.
Save contactHow do I schedule an appointment?
Call (323) 773-7000 to speak with our team and arrange a time.
What should I bring?
Your document list depends on the service. Explore the service pages for a starting checklist, then confirm what is needed with our office.
How do I access the client portal?
The secure portal link is awaiting connection in this redesign preview. Call our office for approved document-sharing instructions.
Do not send Social Security numbers, tax documents or financial account information through ordinary email.
Do you work with businesses and nonprofits?
Yes. Our services include corporate tax, nonprofit tax, bookkeeping, payroll, and corporation formation and compliance. Contact us to discuss your specific needs.