A leaked listing on Apple’s Sales Web (ASW) page, which provides detailed information on all of Cupertino’s products, revealed an important detail on the new iPhone 12 series’ 5G connectivity. You won’t be able to use dual SIMs while on 5G. You can either have your regular SIM card and eSIM working at up to 4G LTE speeds or use one of them on 5G. Dual SIM connectivity will automatically drop new iPhones to 4G speeds.

iPhone 12 FAQ on ASW website

The discovery was shared on r/verizon by user ctthrow1 who managed to get hold of the FAQ document meant for retailers and carriers. It clearly states: “When using two lines in Dual SIM mode, 5G data isn’t supported on either line and will fall back to 4G LTE. If customers are using eSIM only and are on a 5G-supported carrier and service plan, they’ll have 5G access. ”

According to speculation, Apple will address this via software update before the year’s end though it remains to be seen if that will indeed be the case