100W: California Corporation Franchise or Income Tax Return - Water's-Edge Filers (2025)
California · FTB · Used for tax years 2025
Form 100W is the 2025 California Corporation Franchise or Income Tax Return for water’s-edge filers. It reports income, California adjustments, deductions, credits, taxes, and payments to determine a refund or amount due.
Who files this form
Form 100W is California’s corporation franchise or income tax return for water’s-edge filers. The 2025 form identifies the return as filed under a water’s-edge election under R&TC Section 25113 and asks for the election’s starting date.
The supplied form does not state the full rules for when a corporation must file.
What you'll need
Have the corporation’s identifying information, income and deduction records, and payment information available, including:
- Corporation name, address, California corporation number, FEIN, and California Secretary of State file number.
- Water’s-edge election starting date and information about ownership and any combined reporting group.
- 2025 estimated tax payments, withholding reported on Forms 592-B and/or 593, extension payments, and any prior-year overpayment allowed as a credit.
Depending on the entries that apply, the form calls for supporting documents such as:
- Form FTB 3885 for California depreciation adjustments.
- Schedule H (100W) for intercompany dividend elimination and dividend deductions.
- Schedule R if apportioning or allocating income.
- Schedule P (100W) for alternative minimum tax.
- Supporting schedules for other additions and deductions.
- Federal Form 8886 for each reportable or listed transaction included in the return.
A first return for a corporation that succeeds a previous business requires a statement with that business’s name, address, and FEIN, SSN, or ITIN.
Common mistakes
- Leaving the business activity code blank. Schedule Q, question F, specifically says not to leave it blank.
- Missing a separate property-related filing. The form warns that a “Yes” answer to Schedule Q’s property and ownership questions C.1, C.2, or C.3 requires filing a BOE-100-B statement. Penalties may apply.
- Overlooking the minimum franchise tax reminder. Lines 23 and 28 say the amount must be at least the minimum franchise tax, if applicable. The supplied form does not give that minimum amount.
Questions people ask
Can an overpayment be applied to next year’s estimated tax?
Yes. Line 39 lets the corporation designate an amount from its overpayment to be credited to 2026 estimated tax.
Does the form provide for direct deposit of a refund?
Yes. The refund area asks for a routing number, account number, and checking or savings account type. It refers filers to the instructions for direct deposit details.
Must every corporation complete Schedules L, M-1, and M-2?
Not necessarily. The form says the corporation may not be required to complete these schedules and refers to the Schedule M-1 instructions for reporting requirements. Those instructions were not supplied.
Who signs the return?
The signature area calls for an officer’s signature, title, date, and telephone number. It also has a separate paid preparer section.