How to File an Extension for Income Taxes

It happens to the best of us. As the April 15 deadline approaches, you may find yourself waiting on a corrected K-1, organizing a shoebox of receipts, or simply needing more time to ensure your return is accurate. The good news is that requesting an extension is a standard, approved administrative process that does not increase your audit risk. However, there is one critical rule you must understand before you file.

Extension to File ≠ Extension to Pay

This is the most common misconception taxpayers face. An extension gives you six additional months to file your paperwork (usually until October 15), but it does not give you more time to pay the tax you owe.

To avoid penalties and interest, you must estimate your total tax liability and pay any balance due by April 15. If you file an extension but do not pay what you owe, the IRS and state tax agencies will charge interest and late-payment penalties from the very first day past the deadline. We recommend you pay an extra amount as a buffer in case your estimate ends up being too low. You can have any excess payments refunded to you when you file your actual tax return.

Even if you cannot pay by April 15, filing an extension, even without a payment, will significantly reduce your late penalties.

If you will not owe any money with your tax return filing, no payment is required and there would be no late filing or late payment penalties.

How to File a Federal Extension (IRS)

For your federal taxes, you must affirmatively request an extension. If you do not file the request by April 15, you are considered late.

Electronic Extension Request (Recommended)

If you make an extension payment electronically, you do not need to file a paper form. The act of paying designates the extension automatically. The online submission process only takes a few minutes.

Go to IRS Direct Pay.
In the "Step 1" screen, select the following options:
- Select "Extension" as the "Reason for Payment."
- Select "4868 (for 1040, 1040A, 1040EZ)" as the form that you are to "Apply Payment To."
- Select the tax year the extension is for (e.g., 2024 for a tax extension for tax year 2024 when filing it in early 2025).
Complete the "Step 2" screen with information from your prior year tax return.

This is for identity verification purposes.

Complete the "Step 3" screen with your bank details to arrange an electronic withdrawal for your tax payment.

This method requires you to make a payment, even if you do not expect to owe money. You are allowed to make a $1 payment.

The "Step 4" is where you will review your inputs and electronically sign the extension request prior to submitting the form.
Save the confirmation page in the "Step 5" screen for your records.

Paper Extension Request

If you are not making a payment (perhaps you expect a refund or have already paid in full), or if you prefer to mail a check, you must file IRS Form 4868 on paper.

We do not recommend requesting an extension by paper as there can be uncertainty if the postal service does not deliver the mail correctly or if the IRS somehow loses your extension request form. In addition, the paper version of the extension request requires you you to include more information than filing electronically, specifically your estimate of your total tax liabiltiy and the total of your tax payments and withholdings. Also, the government is mandating the IRS transition away from accepting paper checks, which may go into effect at any moment.

Below are some notes on filling out some of the lines on the form:

You must enter your best estimate of the total tax you will owe for the year (Line 4).

Listing an unreasonable number or a number that is significantly different than what your actual tax reteurn will file may result in the IRS rejecting your extension request at a later date.

Enter what you have already paid via withholdings or estimated quarterly payments (Line 5).
Subtract your payments from your liability. This is the amount you should pay to avoid interest.
Ensure it is postmarked by April 15 of the year following the tax year.

How to File a California Extension (FTB)

"Automatic" Extension

California grants an automatic six-month extension to file your state tax return. You do not have to submit a formal extension request, unlike the IRS extension request for federal income taxes.

If you do not owe money: You do not need to file any forms. You do not need to log in to click a button. You automatically have an extra six months to file your California income tax return (that is October 15 for individual/personal taxes).
If you DO owe money: You must pay your balance by the regular filing deadline (April 15 for individual/personal incometaxes) to avoid late penalties.

Electronic Extension Payments

The most reliable way to secure your extension is to pay online. It only takes a few minutes to submit the extension payment online.

Visit the FTB Web Pay portal.
Enter your Social Security Number, name, and address to let their system properly apply the payment to your tax account.
Select "Extension Payment (Form 3519)" as the payment type.
Select the correct tax year (for tax year 2024 which you are filing an extension for in early 2025, you would select "2024" for the tax year).
Enter the amount you are paying in the "Payment Amount" field.
For the payment date, make sure it is not after April 15 to avoid penalties.
If you will be filing a joint return with your spouse, select "Yes" for the question "Is this a joint tax payment?" If you are filing separately from your spouse or if your marital status it not married, answer "No" to that question.
Fill out your bank details for the account you wish to make an electronic withdrawal for the extension payment.
Confirm and submit the extension payment.
Save a copy of the confirmation page for your records.

Note that for taxpayers with total tax liability exceeding $80,000 or your extension payment is over $20,000, you are required to pay electronically. Paying by check may result in a penalty.

Paper Check (Form FTB 3519)

If you must pay by check, download Form FTB 3519 (Payment for Automatic Extension for Individuals) (Google it or find it on the CA FTB website, we are not providing a link here as the PDF link changes). Make sure you download the version for the tax year you are requesting an extension for. Detach the voucher, include your check, and mail it to the Franchise Tax Board.

Note that this guide is intended for informational and educational purposes only. We do not take responsibility for any errors or mistakes caused by your use of the information contained on this article or website.