Resources | Recent News

Important Year-End Notice: New USPS Rule May Affect Last-Minute Mail  

December 22, 2025
Important Year-End Notice: New USPS Rule May Affect Last-Minute Mail  

If you’re planning to mail a contribution check on or before December 31 to claim a charitable tax deduction for 2025, there’s an important change you need to know. 

The U.S. Postal Service recently updated its rules about postmarks. Starting December 24, postmarks are applied at regional processing centers, which may not be your local drop-off point, or where you dropped it in the mailbox. This means a check mailed on or before December 31 could show a January postmark, and the IRS may treat your gift as made in 2026. 

We want to help ensure your gift counts for 2025. 

If you’re still planning to mail a check for a 2025 contribution, we do not recommend relying on a mailbox drop. Instead: 

  • Go to the post office counter and hand your envelope to a USPS staff member and ask for one of these options to confirm the mailing date:  
    • Postage Validation Imprint – printed when you buy postage at the counter.
    • Manual Postmark – stamped by a USPS employee at the counter. 
    • Certificate of Mailing, Certified Mail, or Registered Mail – all provide proof of mailing date. 
  • If you are using UPS or FedEx, checks must be delivered on or before December 31.   
  • If you are in the Kansas City area, you can drop off a check at our office at 1055 Broadway Blvd., located in downtown Kansas City, Missouri.  
    • Our suite is open with staff available to take your check from 8:30 a.m. until 4 p.m. You can find us on the ground floor, across from the security desk in the lobby.  
    • Please contact Donor Services for after-hours options.  

As a reminder, if you plan to contribute to your fund via check, complete a short online form to notify our team.

If you have questions or need assistance with your year-end giving, we’re here to help. Contact Donor Services at service@growyourgiving.org or 816.842.7444.