Check our 2026 Tax Deadlines For C-Corp Startups or Click for your customized tax compliance calendar by startup hub
In 2026, San Francisco has many unique corporate tax deadlines beyond the traditional April 15th tax return date. Important filing deadlines include the San Francisco Gross Receipts filing deadline of February 28 and the April 1st business property tax filing. Estimated tax payments due dates include April 30th, July 31, and October 31st. See the calendar below for a more complete list.
San Francisco companies with 20+ employees: Post updated Paid Parental Leave Ordinance (PPLO) and Health Care Security Ordinance (HCSO) posters and begin compliance. Keep in mind that SB-83 is a California law that extends Paid Family Leave benefits from 6 weeks to 8 weeks for claims starting on or after July 1, 2020.
Claim Research & Development Tax Credits on Form 941, and file annual Federal Unemployment Tax Act (FUTA) return on Form 940. Use our handy calculator to estimate your possible research and development tax credit.
San Francisco startups should send 1099s to contractors. Send W2s to employees and e-file 1099-MISC for non-employee compensation with the IRS. Or file Form 8809 for a 30-day extension to file W2s and 1099-MISC for non-employee compensation.
San Francisco Annual Gross Receipts Tax filing and payment deadline. Gross Receipts tax rates in San Francisco can vary depending on a company’s gross receipts – and business activity. Work with your accountant to determine if you need to file this; the limits are quite low so many funded startups will need to file.
Delaware Annual Franchise Report filing deadline. Your San Francisco startup will pay a minimum of $400, which increases if you have significant funding.
For San Francisco startups, IRS ACA Compliance 1094-B, 1095-B, 1094-C, and 1095-C filings are due (if paper-filing, due April 1 if eFiling). File Form 8809 for a 30-day extension.
Send 1095-B and 1095-C forms to employees.
IRS 30-day automatic extension: provide Form 1095-B and Form 1095C to employees.
IRS ACA Compliance 1094-B, 1095-B, 1094-C, and 1095-C filings are due (e-file).
SF 571-L Business Property Tax filing due. Initial deadline. According to the San Francisco Assessor’s office, California requires businesses to report their taxable property (machinery, equipment, fixtures, etc.) via a Form 571-L.
Deadline to file California Corporation Franchise or Income Tax Return (Form 100). Minimum amount due is $800.
C Corp Form 1120 Tax Return due. The Federal Form 1120 is the U.S. Corporation Income Tax Return, which the IRS has companies use to report their income, losses, credits, etc., and to figure the income tax liability of the corporation. Can extend the deadline to Oct. 15. All San Francisco startups are required to file this Federal form by this deadline unless they file an extension.
Federal Quarterly Estimated Tax 1st installment (first quarter 2026).
File the R&D Tax Credit Form 6765 with your tax return. Can extend to October 15. We strongly recommend working with a qualified CPA to prepare this form in conjunction with your Form 1120 if your company is going to be acquired by a major technology company, that company’s CFO will use a strong tax team to do due diligence on this.
Due date for San Francisco startup employees to make contributions to Individual Retirement Accounts (IRAs) for 2025 (Employee Benefits).
Q1 Estimated San Francisco Gross Receipts Tax installment payment.
San Francisco startups can claim Research & Development Tax Credits on Form 941.
San Francisco Business Registration Renewal filing due. Payment calculated on gross receipts.
Last day to electronically file the San Francisco Form 571-L Business Property Statement. A 10% penalty will be added.
Delaware Quarterly Estimated Franchise Tax. Pay 40% of estimated annual amount (if annual amount expected to exceed $5,000).
Federal Quarterly Estimated Tax 2nd installment (second quarter 2026).
Q2 Estimated San Francisco Gross Receipts Tax installment payment deadline.
Claim Research & Development Tax Credits on Form 941.
Delaware Quarterly Estimated Franchise Tax. Pay 20% of your estimated annual amount (if annual amount expected to exceed $5,000).
Federal Quarterly Estimated Tax 3rd installment (third quarter 2026).
C Corp Form 1120 Tax Return final due date for San Francisco startups if extension was filed.
Claim your Research & Development Tax Credits on Form 941.
Delaware Quarterly Estimated Franchise Tax, Pay 20% of estimated annual amount (if annual amount expected to exceed $5,000).
Federal Quarterly Estimated Tax 4th installment (fourth quarter 2026).
Click The Links To Learn More About These Filings And 2026 San Francisco Startup Tax Deadlines
San Francisco companies with 20+ employees: Post updated Paid Parental Leave Ordinance (PPLO) and Health Care Security Ordinance (HCSO) posters and begin compliance. Keep in mind that SB-83 is a California law that extends Paid Family Leave benefits from 6 weeks to 8 weeks for claims starting on or after July 1, 2020.
Federal Quarterly Estimated Tax 4th installment (fourth quarter 2025).
Claim Research & Development Tax Credits on Form 941, and file annual Federal Unemployment Tax Act (FUTA) return on Form 940. Use our handy calculator to estimate your possible research and development tax credit.
San Francisco startups should send 1099s to contractors. Send W2s to employees and e-file 1099-MISC for non-employee compensation with the IRS. Or file Form 8809 for a 30-day extension to file W2s and 1099-MISC for non-employee compensation.
San Francisco Annual Gross Receipts Tax filing and payment deadline. Gross Receipts tax rates in San Francisco can vary depending on a company’s gross receipts – and business activity. Work with your accountant to determine if you need to file this; the limits are quite low so many funded startups will need to file.
Delaware Annual Franchise Report filing deadline. Your San Francisco startup will pay a minimum of $400, which increases if you have significant funding.
For San Francisco startups, IRS ACA Compliance 1094-B, 1095-B, 1094-C, and 1095-C filings are due (if paper-filing, due April 1 if eFiling). File Form 8809 for a 30-day extension.
Send 1095-B and 1095-C forms to employees.
IRS 30-day automatic extension: provide Form 1095-B and Form 1095C to employees.
IRS ACA Compliance 1094-B, 1095-B, 1094-C, and 1095-C filings are due (e-file).
SF 571-L Business Property Tax filing due. Initial deadline. According to the San Francisco Assessor’s office, California requires businesses to report their taxable property (machinery, equipment, fixtures, etc.) via a Form 571-L.
Deadline to file California Corporation Franchise or Income Tax Return (Form 100). Minimum amount due is $800.
C Corp Form 1120 Tax Return due. The Federal Form 1120 is the U.S. Corporation Income Tax Return, which the IRS has companies use to report their income, losses, credits, etc., and to figure the income tax liability of the corporation. Can extend the deadline to Oct. 15. All San Francisco startups are required to file this Federal form by this deadline unless they file an extension.
Federal Quarterly Estimated Tax 1st installment (first quarter 2026).
File the R&D Tax Credit Form 6765 with your tax return. Can extend to October 15. We strongly recommend working with a qualified CPA to prepare this form in conjunction with your Form 1120 if your company is going to be acquired by a major technology company, that company’s CFO will use a strong tax team to do due diligence on this.
Due date for San Francisco startup employees to make contributions to Individual Retirement Accounts (IRAs) for 2025 (Employee Benefits).
Q1 Estimated San Francisco Gross Receipts Tax installment payment.
San Francisco startups can claim Research & Development Tax Credits on Form 941.
SF 571-L Business Property Tax due. Final date to avoid 10% penalty.
San Francisco Business Registration Renewal filing due. Payment calculated on gross receipts.
Last day to electronically file the San Francisco Form 571-L Business Property Statement. A 10% penalty will be added.
Delaware Quarterly Estimated Franchise Tax. Pay 40% of estimated annual amount (if annual amount expected to exceed $5,000).
Federal Quarterly Estimated Tax 2nd installment (second quarter 2026).
Q2 Estimated San Francisco Gross Receipts Tax installment payment deadline.
Claim Research & Development Tax Credits on Form 941.
San Francisco 571-L Business Property Tax payment due.
Delaware Quarterly Estimated Franchise Tax. Pay 20% of your estimated annual amount (if annual amount expected to exceed $5,000).
Federal Quarterly Estimated Tax 3rd installment (third quarter 2026).
C Corp Form 1120 Tax Return final due date for San Francisco startups if extension was filed.
Q3 Estimated San Francisco Gross Receipts Tax installment payment.
Claim your Research & Development Tax Credits on Form 941.
Delaware Quarterly Estimated Franchise Tax, Pay 20% of estimated annual amount (if annual amount expected to exceed $5,000).
Federal Quarterly Estimated Tax 4th installment (fourth quarter 2026).
California Statement of Information due. Pay $25. Most corporations file annually by the last day of their registration anniversary month.
Note: The due date for filing federal tax returns in 2026 falls on April 15. The federal extension deadline for 2026 is October 15.
How Much Does a Startup Tax Return Cost? Try Kruze Consulting’s Tax Preparation Pricing Tool.
If your Delaware C-Corp San Francisco funded startup needs tax help contact us today!
San Francisco leads the U.S. and world for launching and scaling startups in 2026, offering an ecosystem with more than 14,500 active companies – far outpacing most other tech hubs. The city is renowned for pioneering innovation in AI, fintech, biotech, ecommerce, Web3, and robotics, with global leaders like OpenAI, Rippling, and Benchling among its standout names. Silicon Valley companies continue to attract top talent from world-class universities and a diverse pool of founders, supported by hundreds of accelerators, investors, and collaborative spaces.
San Francisco startups benefit from access to more than one-third of all global venture capital and an unmatched founder network, but must also navigate complex and unique local tax rules. The most important taxing authorities for San Francisco-based companies remain:
San Francisco’s vibrant community of founders, engineers, and investors, coupled with global leadership in emerging tech sectors, makes it one of the most dynamic and resource-rich environments for ambitious startups in 2026.
In 2026, San Francisco has many unique corporate tax deadlines beyond the traditional April 15th tax return date. Important filing deadlines include the San Francisco Gross Receipts filing deadline of February 28 and the April 1st business property tax filing. Estimated tax payments due dates include April 30th, July 31st, and October 31st. See the calendar above for a more complete list.
San Francisco has a reputation of… how shall we say.. not being afraid to level taxes on businesses. These are in addition to the California corporate taxes, which are a flat 8.84% in 2023 (connect with your tax advisor, as this corporate rate may vary depending on your business’ entity type and industry; most tech startups that we work with in SF will pay around 8.84%). SF also has a gross receipts tax, which levels taxes on the revenue a business earns – this is different than the federal or California tax rates, which are based on taxable income.
The San Francisco Gross Receipts Tax is a tax on the gross receipts of businesses operating within the city of San Francisco. The tax rate varies depending on the type of business and the amount of gross receipts. The tax is typically reported and paid on a quarterly basis. The allocation of gross receipts to San Francisco for taxation purposes varies according to the taxpayer’s business type. It is determined by the gross receipts coming from customers in SF, the payroll expenses for employees in the city, or a mix of both factors. Of course, then the next question is “what are gross receipts?”
Basically, revenue earned in San Francisco. According to the SF Treasurer’s office, gross receipts are “Gross receipts include but is not limited to all amounts that constitute gross income for federal income tax purposes. Gross receipts, including advance payments, shall be included in a taxpayer’s gross receipts at the time such receipts are recognized as gross income for federal income tax reporting purposes.”
This is a unique tax to SF; thankfully there is a revenue minimum that makes it not apply to most startups. San Francisco’s Homelessness Gross Receipts Tax applies an extra tax to the majority of businesses that generate more than $50 million in gross annual receipts within the city. Additionally, businesses that opt for the payroll tax under the alternative “administrative office” tax structure are also liable for an extra 1.5% payroll tax. For businesses and consolidated groups that have gross annual receipts exceeding $50 million from San Francisco sources, this tax introduces an added rate between 0.175% and 0.690%, which varies based on the type of business.
Thankfully, this is another SF tax that doesn’t impact most startups. Starting with the 2022 tax year, San Francisco has introduced an additional tax targeting companies with significantly high executive compensation, known as the “Overpaid Executive Gross Receipts Tax.” This tax is activated when the pay ratio between the company’s highest-paid managerial employee, regardless of their location, and the annualized median compensation of both full-time and part-time employees in San Francisco, exceeds 100:1. Compensation for this calculation includes a wide range of earnings like bonuses and stock options. Companies with an executive pay ratio above this threshold will face an extra tax on their San Francisco gross receipts, which varies from 0.1% to 0.6%, based on the specific pay ratio. You can read our startup CEO salary report here – good thing VC backed founders don’t make that much!
2025 startup tax deadlines are supplied for reference purposes only, and should not be used when making decisions in 2026 or beyond. Always consult your tax professional, and see our disclaimer below.
Click The Links To Learn More About These Filings And 2025 San Francisco Startup Tax Deadlines
San Francisco companies with 20+ employees: Post updated Paid Parental Leave Ordinance (PPLO) and Health Care Security Ordinance (HCSO) posters and begin compliance. Keep in mind that SB-83 is a California law that extends Paid Family Leave benefits from 6 weeks to 8 weeks for claims starting on or after July 1, 2020.
Claim Research & Development Tax Credits on Form 941, and file annual Federal Unemployment Tax Act (FUTA) return on Form 940. Use our handy calculator to estimate your possible research and development tax credit.
San Francisco Annual Gross Receipts Tax filing and payment deadline. Gross Receipts tax rates in San Francisco can vary depending on a company’s gross receipts – and business activity. Work with your accountant to determine if you need to file this; the limits are quite low so many funded startups will need to file.
Delaware Annual Franchise Report filing deadline. Your San Francisco startup will pay a minimum of $400, which increases if you have significant funding.
IRS 30-day automatic extension: provide Form 1095-B and Form 1095C to employees.
SF 571-L Business Property Tax filing due. Initial deadline. According to the San Francisco Assessor’s office, California requires businesses to report their taxable property (machinery, equipment, fixtures, etc.) via a Form 571-L.
Deadline to file California Corporation Franchise or Income Tax Return (Form 100). Minimum amount due is $800.
C Corp Form 1120 Tax Return due. The Federal Form 1120 is the U.S. Corporation Income Tax Return, which the IRS has companies use to report their income, losses, credits, etc., and to figure the income tax liability of the corporation. Can extend the deadline to Oct. 15. All San Francisco startups are required to file this Federal form by this deadline unless they file an extension.
Federal Quarterly Estimated Tax 1st installment (first quarter 2024).
File the R&D Tax Credit Form 6765 with your tax return. Can extend to October 15. We strongly recommend working with a qualified CPA to prepare this form in conjunction with your Form 1120 if you are a high-growth startup – if your company is going to be acquired by a major technology company, that company’s CFO will use a strong tax team to do due diligence on this.
Due date for San Francisco startup employees to make contributions to Individual Retirement Accounts (IRAs) for 2023 (Employee Benefits).
Q1 Estimated San Francisco Gross Receipts Tax installment payment.
San Francisco startups can claim Research & Development Tax Credits on Form 941.
SF 571-L Business Property Tax due. Final date to avoid 10% penalty.
San Francisco Business Registration Renewal filing due. Payment calculated on gross receipts.
Last day to electronically file the San Francisco Form 571-L Business Property Statement. A 10% penalty will be added.
Delaware Quarterly Estimated Franchise Tax. Pay 40% of estimated annual amount (if annual amount expected to exceed $5,000).
Federal Quarterly Estimated Tax 2nd installment (second quarter 2024).
Q2 Estimated San Francisco Gross Receipts Tax installment payment deadline.
Claim Research & Development Tax Credits on Form 941 .
San Francisco 571-L Business Property Tax payment due.
Delaware Quarterly Estimated Franchise Tax. Pay 20% of your estimated annual amount (if annual amount expected to exceed $5,000).
Federal Quarterly Estimated Tax 3rd installment (third quarter 2024).
C Corp Form 1120 Tax Return final due date for San Francisco startups if extension was filed.
Q3 Estimated San Francisco Gross Receipts Tax installment payment.
Claim your Research & Development Tax Credits on Form 941.
Delaware Quarterly Estimated Franchise Tax, Pay 20% of estimated annual amount (if annual amount expected to exceed $5,000).
Federal Quarterly Estimated Tax 4th installment (fourth quarter 2024).
California Statement of Information due. Pay $25.
View tax compliance dates for Austin, Boston, New York City, Palo Alto, San Francisco, Santa Monica, Seattle, Washington DC, Atlanta, Salt Lake City, Mountain View, Chicago, Dallas, Miami, and San Jose
How Much Does a Startup Tax Return Cost? Try Kruze Consulting's Tax Preparation Pricing Tool.
How much can your startup save in payroll taxes? Estimate your R&D tax credit using our free calculator.
Every startup is different and so are its tax compliance needs. This is only a guideline. Please consult your tax professional. IRS Circular 230 Disclaimer: To ensure compliance with IRS Circular 230, any U.S. federal tax advice provided in this communication is not intended or written to be used, and it cannot be used by the recipient or any other taxpayer for the purpose of avoiding tax penalties that may be imposed on the recipient or any other taxpayer. Copyright © Kruze Consulting
Check our 2026 Tax Deadlines For C-Corp Startups or Click for your customized tax compliance calendar by startup hub
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Founder & CEO, Vanessa Kruze, is a CPA, Deloitte Tax alumni, and former Controller of a 120+ FTE startup. Our Staff Accountants and Controllers come from the Big 4 and venture backed startups.
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