California LLC Tax and Fee Calculator — connector documentation

MCP endpoint: https://us-ca-llc-fee.connectorbay.com/mcp
REST API: POST https://us-ca-llc-fee.connectorbay.com/v1/tools/{tool_name}, described by the OpenAPI 3.1 spec at https://us-ca-llc-fee.connectorbay.com/openapi.json
Transport: Streamable HTTP, stateless, MCP specification 2025-06-18 or later
Authentication: none required. An optional Authorization: Bearer <key> raises rate limits.
Health: https://us-ca-llc-fee.connectorbay.com/health · Tool schemas: https://us-ca-llc-fee.connectorbay.com/tools.json
Publisher: Unify Dynamics LLC · connectorbay.com/us-ca-llc-fee · agent@connectorbay.com

What California LLC Tax and Fee Calculator is for

Compute a California LLC's $800 annual tax and its income-based LLC fee from owner-supplied figures, check whether the first-year $800 exemption (AB 85: organized or registered on or after 2021-01-01 and before 2024-01-01) applies, and get the exact due dates for a tax year: annual tax (Form FTB 3522, the 15th day of the 4th month of the tax year), estimated fee (Form FTB 3536, the 15th day of the 6th month) and the Form 568 return with its extension. Weekend and holiday due dates move to the next business day as the Franchise Tax Board states, and the response shows both dates. Fee brackets: $250,000-$499,999 $900; $500,000-$999,999 $2,500; $1,000,000-$4,999,999 $6,000; $5,000,000 or more $11,790. Every figure carries its FTB source, date read and verification level; the wording difference between two FTB pages on the Form 568 extension is flagged. General information only: nothing is filed or paid.

Ask your assistant things like:

"My California LLC had $730,000 of total income. What is the LLC fee, and what do I owe in total with the $800 tax?"
"My LLC was registered in California on 15 August 2022. Did it owe the $800 in its first year?"
"When is the $800 annual tax due for a new LLC that filed with the Secretary of State on 18 June 2026?"
"When are Form 568 and its extension due for the year ending 31 December 2026?"
"List all my California LLC's tax dates for 2026 so I can add reminders."

What it does

annual_tax_due: Return the $800 annual LLC tax and its due date (the 15th day of the 4th month of the taxable year) for a taxable year, with the first-year exemption applied where it covers the year.
llc_fee: Return the California LLC fee for total income (zero below $250,000; $900; $2,500; $6,000; $11,790) with the bracket and the definition of total income.
first_year_exemption: Check whether an LLC filed with the Secretary of State on or after 2021-01-01 and before 2024-01-01 and so had the AB 85 first-year exemption from the $800 tax.
form_568_due: Return the Form 568 due date (the 15th day of the 3rd month after the close of the tax year) and the extended date, with the weekend and holiday rule.
estimated_fee_due: Return the Form FTB 3536 estimated LLC fee due date (the 15th day of the 6th month of the tax year) and the underpayment penalty rule.
annual_calendar: List every California LLC date for one taxable year (annual tax, estimated fee, Form 568, extended Form 568) with amounts and the weekend rule, for the owner to approve as reminders.

Data sources

Reference data from official sources (ftb.ca.gov); every answer states its source, date and validity period.

What it is not

California LLC Tax and Fee Calculator is independent; not affiliated with, endorsed by or operated by any government body, central bank, standards body or scheme operator. Names of rails, schemes and standards are used only to say what a tool works with. It is read-only: it never sends, pays, files or signs anything for you, and it never looks up private individuals.

Not advice. General information only, not legal, tax, accounting or payment advice. California LLC Tax and Fee Calculator is an independent tool: it is not affiliated with, endorsed by or operated by any government body, central bank, standards body or scheme operator. Rates, thresholds and rules change; check the cited official source and confirm with a qualified professional before you rely on a result.

Built for: United States. Languages: English.

Tools

Reference & guides

annual_tax_due — Return the $800 annual LLC tax and its due date (the 15th day of the 4th month of the taxable year) for a taxable year, with the first-year exemption applied where it covers the year. Use for "When is the $800 California LLC annual tax due for 2026, and what about a new LLC formed on 18 June 2026?". Args: tax_year_start, sos_filing_date.

llc_fee — Return the California LLC fee for total income (zero below $250,000; $900; $2,500; $6,000; $11,790) with the bracket and the definition of total income. Use for "My California LLC had $730,000 of total income. What is the LLC fee?". Args: total_income.

first_year_exemption — Check whether an LLC filed with the Secretary of State on or after 2021-01-01 and before 2024-01-01 and so had the AB 85 first-year exemption from the $800 tax. Use for "My LLC was registered in California on 15 August 2022. Did it owe the $800 in its first year?". Args: sos_filing_date.

form_568_due — Return the Form 568 due date (the 15th day of the 3rd month after the close of the tax year) and the extended date, with the weekend and holiday rule. Use for "When is my California LLC's Form 568 due for the year ending 31 December 2026?". Args: tax_year_end.

estimated_fee_due — Return the Form FTB 3536 estimated LLC fee due date (the 15th day of the 6th month of the tax year) and the underpayment penalty rule. Use for "When do I have to pay the estimated LLC fee for 2026?". Args: tax_year_start.

annual_calendar — List every California LLC date for one taxable year (annual tax, estimated fee, Form 568, extended Form 568) with amounts and the weekend rule, for the owner to approve as reminders. Use for "List all my California LLC's tax dates for 2026.". Args: sos_filing_date, tax_year, fiscal_year_end_month, total_income.

Conventions

Read-only. Every tool reads public data or computes; nothing is written anywhere and nothing about the user is stored.
Result envelope. ok: true with data, or ok: false with a structured error (bad_input, not_found, upstream_error). degraded lists optional sources that were unreachable.
Rate limits. Free tier 60 tool calls/minute and 300/day per user (keyed on the user identifier supplied by the host agent, else client IP); Pro keys raise this. Over-limit calls return HTTP 429 with Retry-After. initialize and tools/list are never counted.

Support

agent@connectorbay.com · connectorbay.com/us-ca-llc-fee/support