Important Dates

March 16, 2026

Deadline for filing Partnership Tax Return (1065) or filing extension
Deadline for filing S-corporation Tax Return (1120-S) or filing extension

April 15, 2026

Deadline for filing Individual Tax Return (1040) or filing extension
Deadline for filing C-corporation Tax Return (1120) or filing extension
Deadline for filing Fiduciary, Trust, & Estate Returns (1041) or filing extension

May 15, 2026

Texas Franchise Tax Return Due or filing extension

For more information visit the Texas Comptroller website here: https://comptroller.texas.gov/taxes/franchise/

September 15, 2026

Deadline for filing Extended Partnership Tax Return (1065)
Deadline for filing Extended S-corporation Tax Return (1120S)

October 15, 2026

Deadline for filing Extended Individual Tax Return (1040)
Deadline for filing Extended C-corporation Tax Return (1120)

(The last appointment day for 2025 tax returns will be October 2nd)

See link for important additional dates: https://www.irs.gov/pub/irs-pdf/p509.pdf

 *Deadlines for Partnerships and S-corps are actually defined as the 15th day of the 3rd month following the close of the entity’s year

Quarterly Payment Deadlines

Estimated Tax Deadlines for 2026

Payments for estimated taxes are due on four different quarterly dates throughout the year.

Estimated tax payments are due as follows:

    • Q1: April 15 - for income earned January 1 to March 31

    • Q2: June 15 - for income earned April 1 to May 3

    • Q3: September 15 - for income earned June 1 to August 31

    • Q4: January 15 of the following year - for income earned September 1 to December 31

**Quarter 4 for 2025 tax year is due January 15, 2026 **

Note: If these due dates fall on a Saturday, Sunday or legal holiday, the payments are due the next business day.

You may send estimated tax payments with Form 1040-ES. Better yet; you can pay online, by phone or from your mobile device using the IRS2Go app. Visit IRS.gov/payments to view all the options.

If you choose to mail in your payment using a payment voucher, we highly suggest you send it certified mail. This method gives you the ability to track your payment.

Paying online through the IRS.gov website is the easiest and fastest way to make your payment.  You do not have to set up an IRS account to make a payment.  You can select to either pay directly from your bank account or pay with a credit card.  

As you prepare to make your estimated tax payment, please ensure you select "Estimated Tax" as the reason for your payment. It is crucial to use the taxpayer's name and Social Security number. The taxpayer is typically the first person listed on your tax return (usually the husband).

Even if you file as Married Filing Jointly (MFJ), the IRS may not always correctly associate your payment with your account if you use the spouse's name (typically the wife) and Social Security number.

After completing your payment, please take a screenshot or print the confirmation page for your records. This will serve as your only proof of payment.

Please call or email our office if you have any questions.
832.680.2829  info@simplifytax.com