How to Fill Out California Form 100 (w/Examples) + FAQs

California Form 100 is the Franchise or Income Tax Return that every C corporation doing business in California, incorporated in California, or earning California-source income must file with the California Franchise Tax Board. Filing Form 100 correctly determines whether your corporation pays the 8.84% corporate tax rate on net income or the $800 minimum franchise tax, and a single misplaced number can trigger penalties, interest, and a suspension of your corporate powers under R&TC §23301.

According to the FTB’s annual report, California processes more than 750,000 corporate returns each year, and roughly 1 in 6 are filed late or with errors serious enough to generate a notice. This guide walks you through the 2025 revision of Form 100 (filed in 2026) line by line, with three full scenarios, named examples, and field-level fixes so you can file once and file right.

• 📄 What Form 100 is, who must file it, and the statutes that drive every box
• 🧾 A line-by-line walkthrough of every page, schedule, and signature block
• 👥 Three filled-out examples covering a first-year corp, a multistate corp, and a dissolving corp
• 💸 Every filing channel, fee, deadline, and penalty you need to anchor before April 15
• ⚠️ The ten most common Form 100 mistakes and exactly what each one costs you

What Form 100 Is and Who Must File It

California Form 100, the California Corporation Franchise or Income Tax Return, is the annual return used by C corporations to report income, deductions, credits, and tax owed to the state. The form is governed by R&TC §23151, which imposes the franchise tax on every corporation doing business in California, and R&TC §23153, which sets the $800 minimum franchise tax. The current revision is dated 2025 and applies to taxable years beginning on or after January 1, 2025.

You must file Form 100 if your corporation is incorporated in California, qualified to transact business in California through the Secretary of State, or doing business in California within the meaning of R&TC §23101. Doing business now includes any corporation with California sales over the indexed threshold ($735,019 for 2025), California property over $73,502, or California payroll over $73,502. Ignoring this threshold is one of the costliest mistakes a multistate corporation can make, because the FTB can assess back franchise tax, the $800 minimum for each open year, and penalties under R&TC §19131.

S corporations file Form 100S, water’s-edge filers use Form 100W, and exempt organizations file Form 109 or 199. A corporation that elects S status federally but has not elected it in California still files Form 100. A misconception that trips up new filers is the belief that an LLC taxed as a C corp also files Form 100; it does not, unless it has affirmatively elected corporate treatment with both the IRS and the FTB.

Before You Start: Documents and Information You Need

Gathering documents before opening the form prevents the back-and-forth that drags a one-hour filing into a one-week ordeal. The FTB instructions for Form 100 list more than a dozen attachments, and missing even one can stall processing.

• Federal Form 1120 for the same tax year, because California starts with federal taxable income on Line 1 and the FTB requires a complete copy attached.
• California Secretary of State entity number (7 digits) or California Corporation Number, which appears on your incorporation certificate.
• Federal Employer Identification Number (FEIN), used for cross-matching with IRS records; a mismatch triggers a hold.
• California identification of officers and registered agent, because the signature block and Schedule Q require current officer data.
• Prior-year Form 100 to pull NOL carryovers, credit carryovers, and overpayment applied to 2025 estimated tax.
• Estimated tax payments and Form 5806 history, since the FTB cross-references Form 100-ES deposits before posting your return.
• Schedule R apportionment data if you operate in more than one state, including California sales, property, and payroll for the single-sales-factor formula under R&TC §25128.7.
• Depreciation schedules showing federal vs. California differences, because California has not conformed to bonus depreciation under IRC §168(k).
• Credit documentation, such as Form 3523 for the research credit, Form 3554 for the new employment credit, or Form 3805Q for NOLs.
• Bank account information for direct debit through Web Pay, or a check made payable to Franchise Tax Board with the FEIN and 2025 Form 100 written on the memo line.

Aisha, a first-year incorporator in San Diego, learned the hard way that missing her Secretary of State entity number forced the FTB to assign a temporary ID, which delayed her refund by eleven weeks. Marcus, a multistate CFO based in Sacramento, keeps a one-page apportionment workbook ready every January so Schedule R never holds up his return.

Where to Get the Form and How to Access It

The official 2025 Form 100 is available as a fillable PDF on the FTB’s forms and publications page, and the matching instruction booklet sits at the 2025 Form 100 Booklet. The booklet is the controlling document because it incorporates conformity changes, indexed thresholds, and any mid-year legislative updates.

Most corporations are required to e-file under R&TC §18621.10, which mandates electronic filing for any corporation that prepares its return using tax software. E-filing is done through an FTB-approved provider such as Drake, Lacerte, ProSeries, CCH Axcess, or UltraTax; the list is maintained on the e-file for business page. Paper filing is allowed only when the corporation has a waiver under FTB Form 8454 or qualifies as a low-volume filer.

Janet, a controller in Fresno, downloads the form every January, prints the booklet, and tabs the pages she uses most: Side 1 (header and tax), Schedule J (add-on taxes), Schedule P (credit limits), and Schedule R (apportionment). A common misconception is that prior-year forms are interchangeable; they are not, because the rates, indexed thresholds, and conformity dates change every year.

Step-by-Step: How to Fill Out Form 100 Line by Line

The form runs six pages and includes Schedules J, P, Q, R, and V. Work top to bottom on Side 1, then complete the schedules in the order they feed back into the main page. Sample entries below are italicized so you can tell them apart from instructions.

Taxable Year and Fiscal Year Dates (Top of Side 1)

This field asks for the beginning and ending dates of your taxable year. Enter them in MM/DD/YYYY format, even if your tax year is a calendar year. For a calendar-year filer the entry is 01/01/2025 through 12/31/2025; for a June fiscal year it is 07/01/2025 through 06/30/2026. A nuance: a short-period return for a newly formed corporation starts on the date the Secretary of State accepted Articles of Incorporation, not January 1. The most common mistake is leaving the boxes blank on a calendar-year return because the filer assumes calendar year is the default; that triggers an FTB letter requesting clarification and can push the return into the late-filed bucket. A widespread misconception is that the dates must match the federal Form 1120; they must, unless the corporation has a properly approved change of accounting period under IRC §442.

Corporation Name, Address, and Identification Numbers

This block asks for the legal name of the corporation, its mailing address, its California corporation number, and its FEIN. Enter the name exactly as it appears on the Articles of Incorporation, all in capital letters, with no abbreviations unless the legal name uses them. BLUEWAVE LOGISTICS INC. at 1450 MISSION ST, SAN FRANCISCO CA 94103, with California corporation number 4123456 and FEIN 84-1234567, is a proper entry. If the corporation uses a DBA, that goes on a separate line marked “DBA” and never replaces the legal name. The most common mistake is transposing two digits of the FEIN, which causes the FTB’s matching system to reject the e-filed return within 48 hours. A frequent misconception is that the California Secretary of State file number and the FTB account number are the same; the corporation number is a seven-digit ID assigned at incorporation, while the FTB may also assign a separate account ID for tax purposes.

Question A: First Return

This box asks whether this is the corporation’s first California return. Check Yes if the corporation incorporated, qualified, or began doing business in California during the 2025 tax year. A first-year corporation is exempt from the $800 minimum franchise tax under R&TC §23153(f) for its first taxable year, but still owes tax on net income at 8.84%. The nuance most filers miss is that the first-year exemption was repealed for corporations that incorporated in 2024 and later under SB 1106, so verify the rule applicable to your incorporation date. Failing to check Yes when applicable causes the FTB to bill the $800 minimum, and recovering it requires filing an amended return. The misconception here is that “first return” means first year of profit; it means first year of existence or qualification in California.

Question B: Final Return

This box asks whether the corporation is filing a final return because it is dissolving, withdrawing, merging, or no longer doing business in California. Check the appropriate sub-box for Dissolved, Surrendered, Merged/Reorganized, or Other, and write the effective date in MM/DD/YYYY format. A dissolving California corporation must also file a Certificate of Dissolution with the Secretary of State and clear all tax liabilities before the FTB will release the corporation. The most common mistake is checking Final without filing the Certificate of Dissolution, which leaves the corporation legally alive and on the hook for the $800 minimum every year. A misconception is that ceasing operations ends the franchise tax obligation; only formal dissolution or surrender does.

Question J: Accounting Method

This field asks which accounting method the corporation uses: cash, accrual, or other. Mark the box that matches the method used on the federal return; California conforms to the federal method under R&TC §17551. For most C corporations with average gross receipts over $29 million, accrual is required; smaller corporations may elect cash. The mistake to avoid is checking Cash on Form 100 while filing federal Form 1120 on the accrual basis, which triggers an automatic mismatch notice. A misconception is that the corporation can switch methods just by checking a different box; a Form 3115 application must be filed with the IRS, and California follows that change.

Line 1: Net Income (Loss) Before State Adjustments

This line asks for federal taxable income from Form 1120, Line 28, before the federal net operating loss deduction and special deductions. Enter the amount exactly as it appears on the federal return, rounded to whole dollars. $412,750 is a clean entry; entering 412,750.42 is wrong because Form 100 requires whole dollars. The nuance is that pre-2018 NOLs and special deductions stay on the federal return and are not added back here; only the post-Line 28 figure flows up. The most common mistake is starting with Form 1120 Line 30 instead of Line 28, which double-counts NOLs and understates California income. A misconception is that California taxable income equals federal taxable income; the two diverge significantly on depreciation, dividend treatment, and §199A.

Lines 2 Through 16: State Adjustments

These lines reconcile federal taxable income to California taxable income by adding back items California does not allow and subtracting items California taxes differently. Common add-backs include federal bonus depreciation (California has not conformed since 2002), the federal dividends-received deduction, and any federal NOL deduction taken on Form 1120 Line 29a. Subtractions include California-allowed depreciation differences, the California dividends-received deduction under R&TC §24410, and other state-specific items. For example, Marcus reverses $58,000 of federal bonus depreciation on Line 6 and adds $12,400 in California depreciation on Line 12. The most common mistake is forgetting the bonus depreciation reversal, which understates California income by the full federal write-off. A misconception is that California allows §179 expensing up to the federal limit; California caps §179 at $25,000 with a $200,000 phase-out, far below the federal $1,160,000 limit.

Line 17: Net Income (Loss) After State Adjustments

This line is the sum of Line 1 plus net adjustments from Lines 2 through 16. It represents California-adjusted income before apportionment or NOL deduction. Enter the math result; do not round individual components and then re-round. A nuance: if Line 17 is negative, you may have a California NOL to carry forward under R&TC §24416. The mistake to avoid is transposing add-backs and subtractions, which can flip the sign of Line 17 and either overstate tax or understate a loss. A misconception is that a Line 17 loss eliminates tax; the $800 minimum still applies unless the corporation qualifies for the first-year exemption.

Line 18: Net Income (Loss) for State Purposes

This line is Line 17 multiplied by the California apportionment percentage from Schedule R, Line 18a, if the corporation does business in more than one state. For a California-only corporation, the apportionment percentage is 100%, so Line 18 equals Line 17. $354,210 with a 42.7813% California apportionment becomes $151,556 on Line 18. The nuance is that California uses a single-sales-factor formula for most corporations, but a handful of industries (agriculture, extractive, banking, savings and loan) still use the three-factor formula. The most common mistake is applying the wrong apportionment formula; a savings institution using single sales factor will be reassessed under R&TC §25128. A misconception is that having no California office means zero apportionment; California sales delivered into the state count regardless of where the seller sits.

Line 19: Net Operating Loss Deduction

This line asks for the California NOL deduction carried over from prior years. Enter the amount from Form 3805Q, Line 6, capped at the limits set by R&TC §24416. For taxable years 2024 and 2025, California suspended NOL deductions for corporations with more than $1 million of California taxable income; verify whether the suspension still applies for 2025 before claiming. $24,000 is a typical entry for a small corp using a 2022 NOL. The mistake is claiming an NOL during the suspension period, which the FTB will disallow and assess back tax plus interest. A misconception is that federal NOLs flow to California; they do not, because California tracks its own NOLs on Form 3805Q.

Line 22: Tax

This line is California taxable income (Line 18 minus Line 19) multiplied by 8.84%, the C corporation franchise tax rate under R&TC §23151(e). Banks and financial corporations use 10.84%. $127,556 of California taxable income produces $11,276 of tax. The nuance is that the tax is never less than the $800 minimum franchise tax, even if Line 18 is zero or negative, except in the first taxable year. The mistake is multiplying by the personal income tax rate (1% to 13.3%); those rates never apply to a C corporation. A misconception is that the rate dropped under federal TCJA; California did not conform and the rate has been 8.84% since 1997.

Line 23: Schedule J Total

This line pulls add-on taxes from Schedule J, including the LIFO recapture tax, installment sale interest, and the credit recapture from prior years. Enter the total from Schedule J, Line 6. A nuance: a corporation with no LIFO inventory, no installment sales, and no recaptured credits leaves this line blank. The mistake is forgetting to recapture the new employment credit when employment falls below the qualifying threshold; the FTB cross-checks payroll filings and will assess the recapture with a 20% penalty. A misconception is that Schedule J only applies to large corporations; any corporation with a prior credit subject to recapture must file it.

Line 30: Estimated Tax Payments and Withholding

This line totals quarterly estimated tax payments made on Form 100-ES, any prior-year overpayment applied, and any withholding from Forms 592-B or 593. Enter the sum, and attach the supporting forms. $8,000 of estimated payments plus $2,400 of withholding equals $10,400. The nuance is that the first estimate is due on the 15th day of the 4th month of the tax year (April 15 for calendar-year filers), and corporations expecting more than $800 of tax must pay estimates or face an underpayment penalty calculated on Form 5806. The most common mistake is taking credit for estimates the FTB has not posted; always reconcile to MyFTB before filing. A misconception is that federal estimates count for California; they do not, because the two systems are entirely separate.

Line 34: Amount Due or Refund

This line is the tax minus credits and payments. A positive number is the balance due, payable by the original due date even if the corporation extends. A negative number is a refund, which can be applied to next year’s estimates on Line 35 or refunded by direct deposit. $2,376 due is paid via Web Pay or check. The mistake is filing for extension on Form 3539 without paying the balance; the extension is automatic for filing but not for payment, and interest accrues from the original due date. A misconception is that a refund is automatic within four weeks; e-filed refunds typically take 3 to 4 weeks, but paper returns can take 12 weeks or more.

Schedule Q: Questions

Schedule Q asks about ownership, accounting method, and prior FTB activity. Answer every question, even when the answer is No; leaving a question blank causes the e-file system to reject the return. Question 1 asks whether the corporation is a member of a combined reporting group; Question 3 asks about ownership in pass-through entities. The mistake is checking No to combined reporting when the corporation is actually unitary with a parent; the FTB unitary audit team flags inconsistent answers across affiliated returns. A misconception is that Schedule Q is optional; it is part of the return and signing Side 1 attests to its accuracy.

Schedule R: Apportionment and Allocation

Schedule R apportions income between California and other states using the single-sales-factor formula. Enter total sales everywhere on Line 1a and California sales on Line 1b; divide to get the California apportionment percentage. A sale of tangible personal property is sourced to California if delivered to a California buyer under R&TC §25135. Sales of services follow market-based sourcing under R&TC §25136. The mistake to avoid is using cost-of-performance sourcing for services; California abandoned that rule in 2013. A misconception is that throwback applies in California; it does not, so sales into states where the corporation is not taxable are simply excluded from the California numerator.

Schedule P: Alternative Minimum Tax and Credit Limitations

Schedule P calculates the corporate AMT and limits the use of business credits. Even though federal AMT was repealed for corporations in 2018, California retained its 6.65% corporate AMT under R&TC §23455. Complete Side 1 and Side 2 if you claim any credits or have AMT preference items. The mistake is skipping Schedule P because you have no preference items; the schedule is required whenever any business credit is claimed. A misconception is that California AMT mirrors federal AMT; the bases, preferences, and rates are different.

Signature Block (Side 6)

The officer signature block asks for the signature of an officer (president, vice-president, treasurer, assistant treasurer, chief accounting officer, or other duly authorized officer), the printed name, title, date, and daytime telephone. The paid preparer block sits to the right and asks for PTIN, firm name, FEIN, and phone. An e-filed return uses Form 8453-C as the signature authorization, retained by the preparer for four years. The mistake is letting a bookkeeper sign as “controller”; California requires an officer signature, and the FTB can reject a return signed by a non-officer. A misconception is that an electronic signature is invalid; e-signatures on Form 8453-C are accepted under FTB Notice 2023-02.

Three Filled-Out Examples Using Real Scenarios

The three scenarios below show how the same form changes shape depending on the corporation’s facts. Each filer is fictional but the numbers track the 2025 rules.

Scenario 1: Aisha’s First-Year California-Only Corporation

Aisha incorporated BLUEWAVE LOGISTICS INC. in San Diego on March 3, 2025, and earned $96,000 of net income in her short first year.

Form Section	What Aisha Enters
Taxable year dates	03/03/2025 to 12/31/2025
Corporation name and address	BLUEWAVE LOGISTICS INC., 1450 MISSION ST, SAN DIEGO CA 92101
Question A: First return	Yes
Line 1: Federal taxable income	$96,000
Line 17: Net income after state adjustments	$96,000
Line 18: Net income for state purposes	$96,000
Line 22: Tax at 8.84%	$8,486
Line 26: $800 minimum tax	$0 (first-year exemption if eligible)
Line 34: Balance due	$8,486
Payment method	Web Pay direct debit

Scenario 2: Marcus’s Multistate C Corporation

Marcus runs PACIFIC IRON WORKS INC., a Sacramento-headquartered manufacturer with $4.2 million of total sales and $1.8 million of California sales.

Form Section	What Marcus Enters
Taxable year dates	01/01/2025 to 12/31/2025
Corporation name and FEIN	PACIFIC IRON WORKS INC., FEIN 84-1234567
Line 1: Federal taxable income	$612,000
Line 6: Bonus depreciation add-back	$58,000
Line 17: Net income after state adjustments	$670,000
Schedule R apportionment	42.8571% (1.8M ÷ 4.2M)
Line 18: California net income	$287,143
Line 22: Tax at 8.84%	$25,383
Line 30: Estimated tax payments	$22,000
Line 34: Balance due	$3,383

Scenario 3: Janet’s Dissolving Corporation

Janet is winding down VALLEY FLOWER CO., a Fresno retailer that ceased operations on June 30, 2025, and filed a Certificate of Dissolution with the Secretary of State.

Form Section	What Janet Enters
Taxable year dates	01/01/2025 to 06/30/2025
Question B: Final return	Yes — Dissolved, 06/30/2025
Line 1: Federal taxable income	($14,200)
Line 17: Net income after state adjustments	($14,200)
Line 18: Net income for state purposes	($14,200)
Line 22: Tax	$0
Line 26: $800 minimum tax	$800 (still owed in final year unless exempt)
Schedule J: Credit recapture	$0
Line 34: Balance due	$800
Attachments	Federal Form 1120, Certificate of Dissolution copy

How to File the Completed Form

Form 100 can be filed electronically, by mail, or in person, and the channel you pick affects processing time and proof of filing. Most corporations are required to e-file under R&TC §18621.10.

E-file (required for most filers). Use any FTB-approved software listed on the e-file for business page. There is no fee charged by the FTB. Acknowledgment arrives within 48 hours, and refunds typically post in 3 to 4 weeks. Keep the software-generated acknowledgment plus Form 8453-C in your records for four years.

Paper filing (only with waiver). Mail returns with a payment to Franchise Tax Board, PO Box 942857, Sacramento CA 94257-0501; returns without payment go to PO Box 942857, Sacramento CA 94257-0500. Use USPS Certified Mail with return receipt, because the postmark date is your filing date under R&TC §21027. Processing takes 8 to 12 weeks.

Payment by Web Pay. Pay the balance due through FTB Web Pay for Business at no cost via bank account. Credit card payments are accepted through ACI Payments with a 2.3% convenience fee. Schedule the debit on or before the original due date to avoid interest.

Extension to file. California grants an automatic 7-month extension to file (6 months for most corporations, 7 months for those in good standing), but the payment is still due by the original due date. File Form 3539 only if you owe a balance with the extension. The original due date is the 15th day of the 4th month after year-end (April 15, 2026 for calendar-year 2025 filers).

What Happens After You File

Once the FTB accepts the return, the corporation receives a confirmation through MyFTB or, for paper filers, a stamped copy if requested. Refunds post by direct deposit within 3 to 4 weeks of e-file acceptance, or 8 to 12 weeks for paper. The FTB has four years from the later of the original due date or actual filing date to audit the return under R&TC §19057, and longer if there is a 25% understatement or no return at all.

If the FTB has questions, you will receive a Notice of Proposed Assessment (NPA) or a Demand for Tax Return. Respond within 30 days to preserve your right to protest under R&TC §19041. Failure to respond turns an NPA into a final assessment and the case moves to collections. Penalties accrue at 5% per month up to 25% for late filing under R&TC §19131, plus 5% per month for late payment under R&TC §19132. Interest compounds daily at the rate set semiannually by the FTB.

Carlos, a CFO in Long Beach, ignored an NPA for 45 days last year and watched a $3,000 tax issue grow into a $7,400 liability with penalties, interest, and a collection fee. Responding within the 30-day window is almost always cheaper than paying and disputing later.

Mistakes to Avoid When Filling Out the Form

The same errors appear on FTB rejection notices year after year. Knowing them in advance saves money and time.

• Filing on the federal due date when California’s is the same day but the address differs, causing the return to be misrouted.
• Forgetting the bonus depreciation add-back on Line 6, which understates California income by tens of thousands of dollars.
• Skipping Schedule P when claiming a research credit, leading to automatic credit disallowance.
• Using federal NOLs on Line 19 instead of California NOLs from Form 3805Q.
• Checking Yes on Question A First Return when the corporation is actually in its second year, triggering an FTB notice and possible fraud flag.
• Sourcing service revenue under cost-of-performance instead of market-based sourcing required under R&TC §25136.
• Paying with extension Form 3539 but missing the original due date, generating a late-payment penalty even though filing was extended.
• Leaving Schedule Q questions blank, which causes e-file rejection within hours.
• Signing as “manager” or “bookkeeper” instead of as an officer.
• Forgetting to attach a complete copy of federal Form 1120, which the FTB will request and which suspends processing until received.

Do’s and Don’ts

A short list of habits separates clean filers from those who get notices.

• Do reconcile estimated payments to MyFTB before filing, because the FTB will not credit payments it cannot match.
• Do keep federal and California depreciation schedules side by side, because the differences drive most adjustments.
• Do check the Secretary of State entity status at bizfileOnline before filing a final return, since suspended corporations cannot dissolve.
• Do sign Form 8453-C the same day the return is transmitted, because the date must match the e-file acknowledgment.
• Do pay the $800 minimum even when filing a loss, unless the first-year exemption applies.
• Do retain the return and supporting workpapers for at least seven years, because the FTB statute can run beyond four years.
• Don’t mix tax years on Form 100-ES coupons; each payment must be coded to the correct year or it will sit unapplied.
• Don’t rely on federal extensions; California requires Form 3539 if you owe.
• Don’t ignore an FTB letter past 30 days, because protest rights expire.
• Don’t assume an LLC taxed as a corporation files Form 100; verify the election.

Pros and Cons of Filing on Your Own vs. With Help

Filing Form 100 in-house is feasible for simple, single-state corporations but expensive when apportionment or credits enter the picture.

Pros of self-filing. It saves the $500 to $2,500 CPA fee for a basic return. It forces the owner to learn the form, which builds long-term tax fluency. It speeds turnaround for simple returns. It keeps sensitive financial data in-house. It allows immediate updates as numbers change before filing.

Cons of self-filing. Missing a Schedule R nuance can produce a five-figure assessment. The corporation loses the preparer’s e-file infrastructure and signature authorization process. There is no professional liability backstop if the return is wrong. NOL and credit carryovers are easy to lose track of across years. Audit support is on the owner alone.

FAQs

Who must file California Form 100?

Yes — every C corporation incorporated in California, qualified to do business there, or meeting the doing-business thresholds under R&TC §23101 must file Form 100, even with no income.

Is the $800 minimum franchise tax owed in the first year?

No — corporations incorporated before 2024 are exempt from the $800 minimum in their first taxable year, but the regular 8.84% tax still applies to net income.

What is the due date for Form 100?

Yes — calendar-year filers must file by April 15, 2026, which is the 15th day of the 4th month after year-end; fiscal-year filers follow the same 4th-month rule.

Can I extend Form 100?

Yes — California grants an automatic 7-month extension to file for corporations in good standing, but any balance due must still be paid by the original due date using Form 3539.

Do I file Form 100 if my corporation had no income?

Yes — a California corporation must file Form 100 every year it exists, even with zero income, and pay the $800 minimum franchise tax unless exempt.

Do I write my California Corporation Number or FEIN at the top?

Yes — Form 100 requires both: the 7-digit California Corporation Number assigned by the Secretary of State and the 9-digit federal EIN, in their respective boxes on Side 1.

What goes on Line 1 of Form 100?

Yes — Line 1 takes federal taxable income from Form 1120, Line 28, before the federal NOL deduction and special deductions, rounded to whole dollars.

Do I check Question A “First Return” if I started mid-year?

Yes — check Yes on Question A in any year the corporation first incorporates, qualifies, or begins doing business in California, regardless of the start date.

Should I attach the federal return?

Yes — Form 100 instructions require a complete copy of federal Form 1120 (or the consolidated portion attributable to the California filer) attached to the return.

Can I e-file Form 100?

Yes — most corporations are required to e-file under R&TC §18621.10 using FTB-approved software; paper filing is allowed only with an approved Form 8454 waiver.

Does California follow federal bonus depreciation?

No — California has not conformed to IRC §168(k) bonus depreciation, so corporations must add it back on Form 100 and depreciate using California rules.

Are federal NOLs deductible on Form 100?

No — California tracks its own NOLs on Form 3805Q, and corporations may not transfer federal NOL amounts directly to Line 19 of Form 100.

What penalty applies for filing late?

Yes — a 5% per month penalty up to 25% applies under R&TC §19131, plus a separate 5% late-payment penalty under R&TC §19132 and daily-compounded interest.

Can I pay Form 100 by credit card?

Yes — credit card payments are accepted through ACI Payments with a 2.3% convenience fee; Web Pay direct debit from a bank account is free.