Using an iPhone 12 in Dual SIM sets the data speed to 4G LTE, according to an Apple Sales FAQ that was shared among carriers and retailers.
The 5G iPhone 12 models support Dual SIM, the capacity between switching between a specific SIM card and an eSIM working on a different number and/or carrier.
However, an image of a seemingly official document from Apple’s Sales Web resources titled “What you need to know about 5G on iPhone” made its way on Reddit, suggesting that the iPhone 12 won’t feature 5G support on either line when the device works in Dual SIM model. This is what the FAQ says:
“Does 5G work with Dual SIM?
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.”
The Meaning Of The Message
The document suggests that the device can tap into 5G speeds only by disabling one or another SIM. Suppose the limitation gets officially confirmed (and it looks like it will, as MacRumors received independent confirmation on the subject). In that case, it will undoubtedly come as a bummer to iPhone 12 customers who desire to use separate sim cards/carriers for work and personal purposes, for example.
However, there might be a silver lining, as the problem might be limited to a software issue, meaning that it can get fixed over time.
The Reddit user who posted the document’s screenshot said that a later update would fix the inconvenience, which is excellent news. It would have been a shame for such a great phone to be affected by a software mishap.