Apple did not immediately respond to CNBC's request for comment. UPS declined to disclose any shipping relationship with Apple—but the company has a temporary service notice posted on its website, detailing the zip codes affected. FedEx said deliveries will continue to operate during the papal visit, although customers may experience service delays.
"We have implemented contingency plans to help mitigate delays," a FedEx spokesman told CNBC. "Our goal is 100-percent reliability, and we appreciate our customers' patience and understanding while our operations teams work to minimize any delays."
The newest iPhone models have been available to pre-order since Sept. 12, with free shipping in many locations. It's unclear exactly how many iPhone are expected for delivery Friday, though the company previously said it was on pace to beat last year's 10 million unit first-weekend record when the new iPhones go on sale Sept. 25.
Though mobile phone sales might not benefit from the pope's upcoming visit, it has boosted other technology companies like Airbnb, which has seen a surge of listings in Philadelphia.
Click here to read the full report on iPhone shipment delays from MacRumors.
The story has been updated with comments from FedEx.