Text messages received overnight on Wednesday caused confusion, misunderstandings and even alarm for some recipients.
The messages appear to have originally been sent on February 14, Valentine's Day, but were received more than eight months later with Wednesday's time stamp.
The issue occurred across all four major carriers in the United States and affected both Apple and Android devices.
People shared their experiences about receiving delayed messages on social media and Reddit. Some said they received text messages from ex-boyfriends and ex-girlfriends that led to awkward conversations. Others said the messages came from relatives or friends who had since passed away. One person complained to Sprint's Twitter account that her phone had sent a text to her boss in the middle of the night.
The person who originally sent the text should have a record of the message in their archives.
The issue seems to have multiple causes, according to carriers that have responded. But it's unclear why most of the messages seem to have been from Valentine's Day.
Sprint said a "maintenance update" caused the incident.
"Last evening, a maintenance update occurred to part of the messaging platforms of multiple carriers in the US, including Sprint, which caused some customers to have older text messages sent to their devices," a Sprint spokesperson told CNN Business. "The issue was resolved not long after it occurred. We apologize for any confusion this may have caused."
T-Mobile said it wasn't an internal issue but rather a problem stemming from a third-party vendor that also affected its networks. A spokesperson said T-Mobile was aware of the issue and it has since been resolved.
Verizon and AT&T, which is CNN's parent company, did not immediately respond to a request for comment. Apple and Google also did not immediately respond.