The modern United States Postal Service (USPS) is changing how long it will take to deliver First-Class Mail. You know, the kind where you put a stamp on an envelope and send it. – Source
If you still send checks in the mail to pay bills you must now allow at least five days for the payment to arrive at the creditor.
Up until now, the service expectation has been one to three days.
Payment is not record until it is received by the creditor. Not mailed. So this new delivery delay can catch people by surprise if they wait till near the due date to send the check.
In fact, I would recommend setting your absolutely last minute to send a payment in the mail one week prior to the due date to allow for weekends.
Alternatively, make your payments online to avoid mail delays entirely.
It is your responsibility to make sure your payment arrives on time to avoid any late fees or penalties.
The new slower delivery times begin October 1, 2021.