The postmark rule isn’t changing, but the postmark process might be.
The Postmark Rule
For decades, North Carolina property taxpayers have benefitted from the “postmark rule” currently codified in GS 105-360(d): “For the purposes of computing discounts and interest, tax payments submitted by mail shall be deemed to be received as of the date shown on the postmark affixed by the United States Postal Service.”
In other words, if a property tax payment is postmarked before the delinquency date (usually January 6), or the date on which a new interest rate applies to delinquent taxes (usually the first of each month), or the date on which discounts must end (September 1), then the tax office is required to treat the payment as if it were received before those due dates. No new interest would accrue on the account or, in the case of discounts, the payment would benefit from whatever discount percentage the local government has in place.
The rule occasionally produces friction with taxpayers. Sometimes the USPS does not apply a postmark. Sometimes mail is marked with a private postmark such as that from a Pitney-Bowes postage machine instead of a USPS postmark.
In those cases, the statute is clear; the tax office must treat all mail without official USPS postmarks as received on the actual date of receipt. GS 105-360(d) states, “If no date is shown on the postmark or if the postmark is not affixed by the United States Postal Service, the tax payment shall be deemed to be received when the payment is received in the office of the tax collector.”
Sometimes the local government does not maintain copies of the envelopes in which payments were mailed, preventing them from determining if or when the payment was postmarked. (To be clear, this is not best practice; payment clearinghouses/lockbox operators should keep evidence of postmarks.) In these situations, taxpayers might have a reasonable argument to benefit from the postmark rule. GS 105-360(d): “In any dispute arising under this subsection, the burden of proof shall be on the taxpayer to show that the payment was timely made.” But exactly how a taxpayer could prove a payment was mailed prior to the due date is unclear (perhaps a time-stamped video of them inserting the payment into a mailbox?).
To avoid taxpayer challenges, some tax offices apply grace periods of a day or two under the assumption that all payments received shortly after the date of delinquency were mailed prior to that date and therefore should not be charged interest.
Would proof that a taxpayer used an on-line bill payment system through their bank be sufficient to trigger the postmark rule? I don’t think so. The fact that the taxpayer asked their bank to send a payment to the tax office prior to the payment deadline is not evidence that the bank actually mailed that payment in a timely fashion. Most banks deduct funds from checking accounts immediately, but the checks are not mailed or delivered electronically until several days later.
While some counties might adopt a more taxpayer-friendly approach, it is legally acceptable for the tax office to treat all payments received from a bank’s automated payment system as made on the date of receipt unless the payment is a physical check that was postmarked prior to the delinquency date.
New Postmark Process?
For decades, the USPS has been postmarking mail at its regional processing centers, not at the post office which first receives the mail. However, most mail was still postmarked on the day it was received by the USPS. That changed with this USPS announcement in late 2025:
“We have made adjustments to our transportation operations that will result in some mailpieces not arriving at our originating processing facilities on the same day that they are mailed. This means that the date on the postmarks applied at our processing facilities will not necessarily match the date on which the customer’s mailpiece was collected by a letter carrier or dropped off at a retail location.”
Recent consolidations of USPS operations means that many post offices will be 150 miles or more away from the facilities that will postmark their mail.
Bottom line: it seems likely that much less mail will be postmarked on the day of mailing in 2026 and beyond than in prior years.
What does this mean for tax offices? It certainly does not change how the postmark rule must be applied. If mail is not postmarked prior the date of delinquency (or new interest rate or the end of the discount period), then the postmark rule cannot apply. Tax offices may not subtract a day from the postmark date to account for the USPS’s new processing system.
However, tax offices might consider providing additional education/warnings to taxpayers about the possibility of delayed postmarks and of the ability to ask for manual postmarks when they drop off mail at their local post offices. Printing this information on tax bills, perhaps on the payment coupons, might be most effective.
These warnings/notifications could be added those already provided by many tax offices about the delay in electronic checks and similar payments. Orange County, for example, uses this language:
Please be advised ACH/eCheck transactions do not post immediately and may take up to 10 business days to process. Therefore, returned payments may occur up to 2 weeks after a payment is initiated. Any payment returned after the delinquent date will accrue interest in accordance with North Carolina law.
