Form FTB 8453-OL: Signing, Retention, and Banking Details

Form FTB 8453-OL is the California e-file authorization you sign when you prepare and transmit your own state income tax return through consumer tax software. You sign it after your return is finished but before your software sends it, because the Franchise Tax Board does not treat an e-filed return as filed without that signature.¹ You keep the completed form. You do not mail it. The FTB will ask for it only if a question comes up later.

Who Should Use This Form

Form FTB 8453-OL is for individuals who prepare and e-file their own California return using self-service software such as TurboTax, H&R Block Online, or CalFile. If a paid preparer files for you, a different authorization applies: Form FTB 8453 covers preparer-filed returns and includes a declaration for the preparer’s credentials,² and Form FTB 8879 is the PIN-based signature authorization used when the preparer transmits on your behalf.³

If you’re at your own computer typing your own numbers, FTB 8453-OL is the one that applies to you. The software will generate it automatically from your return data, but the accuracy of every figure is on you.

Completing Each Part of the Form

The 2025 version of the form has five parts.⁴ Your software populates most fields, but review each one against your return before you sign.

Header and Identification

Enter your first name, last name, suffix if any, and your Social Security Number or ITIN at the top. On a joint return, your spouse’s or registered domestic partner’s name and SSN or ITIN go here too.

Part I — Tax Return Information

Three figures, all in whole dollars:

Line 1 is your California adjusted gross income, taken from the corresponding line on your Form 540 or 540NR.
Line 2 is your refund amount, or zero if you’re not getting one.
Line 3 is the amount you owe, if any.

These have to match your completed return exactly. A mismatch between Part I and the return itself is a common cause of processing delays, so check each line against your software’s final summary screen before you sign.

Part II — Electronic Payment of a Balance Due

If you owe, Part II lets you authorize an electronic funds withdrawal from your bank account. You select the withdrawal option, enter the payment amount, and choose the withdrawal date. The FTB will pull the funds on that date, so the money needs to be there. If the payment fails, you remain liable for the tax plus any interest and penalties.⁴

Part III — Estimated Tax Payments for Next Year

Part III is easy to miss because it looks forward, not back. If you want to authorize electronic estimated tax payments for the next year, enter the amounts and dates here. Most filers leave this section blank and handle estimated payments separately through Form 540-ES or the FTB’s online payment portal.

Part IV — Banking Information

If you’re getting a refund by direct deposit or paying by electronic withdrawal, Part IV holds your bank’s routing number, your account number, and the account type. Errors here are consequential. A wrong routing number can bounce your refund or fail your payment. Verify the numbers against a recent statement or your bank’s online portal rather than typing them from memory.

Part V — Declaration of Taxpayer(s)

Part V is the signature. By signing, you declare under penalty of perjury that the information on the form matches your return and that the return is true, correct, and complete to the best of your knowledge. On a joint return, both you and your spouse or RDP must sign; forging the other signature is unlawful.⁴ A joint return also serves as an irrevocable appointment of each spouse as the other’s agent for receiving refunds or authorizing withdrawals.

When You Sign and How the Signature Works

Sign the form after your return is prepared and before it’s transmitted. An e-filed return isn’t considered filed until the signature is in place.¹ Most tax software builds the signing step directly into the submission workflow, so it’s hard to skip by accident.

The FTB accepts electronic signatures for individually e-filed returns, so you don’t need to print, hand-sign, and scan anything. Your software’s e-signature process satisfies the requirement.⁵

Do Not Mail the Form

“DO NOT MAIL THIS FORM TO THE FTB” appears at the top of the form in bold.⁴ Unlike some federal forms that require a mailed signature page, this one stays with you. Mailing it doesn’t speed anything up. The FTB will contact you directly if they ever need to see it.

What to Keep, and for How Long

After you e-file, hold onto the signed form and its supporting records for as long as California’s audit window stays open. The FTB generally has four years from the return’s due date or four years from the date you filed, whichever is later, to issue an assessment.⁶ Keep your records for at least that long.

Your retention file should include:⁷

The signed Form FTB 8453-OL itself, saved digitally or printed.
Original W-2, W-2G, and 1099-R forms supporting the figures on your return.
A paper copy of your California return (Form 540, 540 2EZ, or 540NR).
A paper copy of your federal Form 1040 for the same year.
Any other state’s return, if you claimed the Other State Tax Credit.

One warning about non-filing: if you never file a return for a given year, no statute of limitations applies at all, and the FTB can assess tax at any time.⁶ That alone is a reason to make sure the signing step actually happens.

Penalties for Errors or a Missing Signature

The declaration on Part V carries legal weight. California Revenue and Taxation Code Section 18621.5 requires a signed electronic filing declaration for any electronically submitted return; without it, the return is not considered filed.⁸ A return that isn’t filed in the FTB’s eyes can trigger the delinquent filing penalty: 5% of the unpaid tax for each month the return is late, up to 25%.⁹

Willfully signing a false or fraudulent return is worse. Under Revenue and Taxation Code Section 19706, it can result in up to a year in county jail or state prison, a fine of up to $20,000, or both, plus the costs of investigation and prosecution.¹⁰ Civilly, the FTB can also impose a fraud penalty equal to 75% of the underpayment attributable to fraud.

If the FTB asks for your signed Form FTB 8453-OL during an audit or inquiry and you can’t produce it, they may treat the return as unsigned and potentially invalid. Retention isn’t optional bookkeeping. It’s your proof that you filed a valid return.

Common Mistakes to Avoid

Mismatched income figures. If your software auto-fills Part I and you later adjust your return without regenerating the form, the numbers won’t agree.
Wrong bank details. Transposed digits in a routing or account number can redirect your refund or fail your payment, and the FTB won’t chase down a misdirected transaction.
Missing spouse signature on a joint return. Both filers must sign or the return is incomplete.
Mailing the form. It says not to. Mailing it doesn’t create a backup, only unnecessary correspondence.
Not retaining the form. Deleting the file or throwing out the printout leaves you unable to respond when the FTB asks for verification years later.

If You Amend Your Return Later

California allows e-filed amended returns for the current tax year and the two prior years, and there’s no separate “amended” version of Form FTB 8453-OL. When you e-file an amended return through self-prepared software, the same authorization form applies. One difference: if your amended return produces a balance due, you use Payment Voucher FTB 3582X rather than the standard FTB 3582 that goes with original returns.³

1
Franchise Tax Board. 2024 Instructions for Form FTB 8453-OL
2
Franchise Tax Board. FTB 8453 – California e-file Return Authorization for Individuals
3
Franchise Tax Board. e-file for Individuals
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Franchise Tax Board. California Form 8453-OL – California Online e-file Return Authorization for Individuals
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State of California Franchise Tax Board. e-Signature Options for e-file
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Franchise Tax Board. Your Tax Audit
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Franchise Tax Board. Instructions for Form FTB 8453-OL California Online e-file Return Authorization for Individuals
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California Legislative Information. California Code Revenue and Taxation Code 18621-5
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Franchise Tax Board. Common Penalties and Fees
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California Legislative Information. California Code Revenue and Taxation Code RTC 19706