Tax Reminders: 2025 Tax Filing Due Dates and Postmark Changes

Tax season is upon us, and there are some important updates to share! The Internal Revenue Service (IRS) opened for the 2026 filing season January 26, which means that now is the perfect time to begin planning what will be needed to file all tax returns. It is crucial to start gathering all required documentation and preparing to meet with a trusted tax advisor, so your returns can be filed in a timely manner without facing penalties or interest.

2025 Filing Due Date Reminders

As we begin this tax season, it is important to remember the return due dates for each filing method. The following table outlines the upcoming deadlines:

The table below highlights the deadlines for Individual 1040 quarterly estimated payments:

It is imperative that all taxpayers understand these deadlines as we enter into tax filing season. While there is the opportunity to extend tax returns, adhering to the normal due date ensures that taxpayers avoid late-filing interest or penalties.

Impact of the Most Recent Postmark Changes on Paper Filing of Returns

The United States Postal Service (USPS) recently adopted a final rule (FR Doc. 2025-20740) adding Section 608.11 “Postmarks and Postal Possession” to the Domestic Mail Manual (DMM), which took effect on December 24, 2025. There have been many misconceptions about the changes that resulted from this new rule, as the USPS reveals in Postmarking Myths and Facts. The USPS shared that the process for postmarking has not changed; rather the transportation operations have been revamped. Hence, the million-dollar question becomes: What is staying the same versus what is changing?

Remaining the Same

The current USPS postmarking practices will remain the same, including postmarks being applied by automated machines at regional processing facilities. These postmarks include the following elements: name and/or location of facility; and date that the first processing operation was performed.

Additionally, customers will still be able to visit a retail location for postal services to request a manual/local postmark for no extra fees. A manual postmark will ensure that the postmark date will be the same day as mailing.

The Real Changes

The implemented changes and public questions, which are outlined in the new DMM Section, include the adjustments being made to the transportation operations. With these changes, some mail will not arrive at the regional processing facilities on the same day as mailing, which may result in the postmark date being later than the date when the customer drops mail into the blue collection boxes or gives it directly to a post office employee. In other words, there will be a delay in postmarking in some cases.

The likelihood that these updates to the transportation processes will delay the mail’s arrival at the regional processing facilities creates some concern for ensuring that paper copies of tax returns are received before the filing deadlines. Taxpayers should be aware of potential delays in postmarking and plan ahead to avoid late filing.

GYF recommends the following solutions:

• Avoid risk: Utilize the opportunity to file returns electronically when applicable
• When electronic filing is not an option, including local returns, consider the following:
  • Best practice: Use Certified Mail with Return Receipt Requested to get a stamped, documented date of filing
  • Mail early (3-5 days should be sufficient, but not guaranteed)
  • In-person handling: Request a manual, hand-stamped postmark from a postal employee at the counter
• If using private transport, like UPS or FedEx, ensure you use a service designated by IRS Notice 2026-30 (ask your tax professional; link is not yet directly available for the public)

As you begin navigating your 2025 tax return filing decisions, please contact your GYF tax professional for expert advice.