It didn't take too long for either carrier to break previous single-day sales records for a smartphone.
AT&T and Sprint Nextel both said that the new iPhone 4S helped drive record single-day sales for each carrier.
Sprint said it reached its best-ever day of sales by 10 a.m. PT. AT&T said that as of 1:30 p.m., it had activated a record number of iPhones on its network.
The new iPhone, despite the lack of a major redesign, continues to be a tremendous draw, significantly outstripping the demand for any other smartphones. The iPhone 4S drew lines at Apple stores around the country.
In addition, the iPhone also continues to be a crucial tool for carriers in retaining and adding customers. Sprint, which is getting the iPhone for the first time, was first out of the gate with an announcement.
Sprint is badly in need of a little good news after a tough week in which its executives failed to answer questions about its relationship with Clearwire and the financial impact of carrying the iPhone. Sprint has said it would disclose the impact during its quarterly results later this month.
The company's previous record was held by the HTC Evo 4G, its first 4G WiMax smartphone, which debuted last summer.
AT&T, meanwhile, doesn't seem to be feeling the effects of a third carrier offering the iPhone. The company added it was on pace to double its previous record for single-day activations.
Verizon Wireless, meanwhile, would only say that sales were "brisk with steady traffic all day." A spokeswoman said the company wasn't going to disclose numbers until Verizon's earnings report next week.