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Comment by guru4consulting | Hacker News Reader

I guess dual SIM is different from having eSIM+physical SIM. Dual SIM typically allows both SIMs/phone-numbers to be active and when you receive a call, you will know which number is being called. With eSIM+physical SIM card, only one can be active at a time. The other has to be disabled. At least, this is what I found few years back.

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Nope, eSIM plus physical SIM in an iPhone or in a Pixel or any other phone work just like 2 physical SIMs. It's been supported in mainstream Android for a few years now. Previously it was supported only on devices with 2 slots and each vendor had their flavor in Android.

I know that iPhones with SIM+eSIM can have both active at the same time, and iPhones with just eSIM can have two eSIMs active.

Yeah I found this out the hard way when travelling recently. There are some great apps that let you buy cheap data-only eSIMs in dozens of countries. You can even buy an eSIM before you travel. It’s crazy convenient and much cheaper than roaming fees.

My girlfriend could keep her home phone line enabled while using the eSIM but I couldn’t, even though we have the same model of phone! Turns out her home line uses a physical sim, but mine is set up using an eSIM and the iPhone 12 can only have 1 eSIM enabled at a time. You can do 1 physical + 1 eSIM, but not 2 esims.

I couldn’t get texts or calls from home without noodling with my phone settings each time. And FaceTime kept enrolling and unenrolling my number.

I’m currently traveling internationally with an iPhone 12 and I can confirm the single eSIM + single physical SIM limitation. Although, in my case, I'm using a physical international SIM and a US eSIM.

I would love to turn off my US eSIM when not in use (I think it uses more power connected to two cellular networks) but that would require unenrolling my US iMessage number and I can’t do that. Definitely the most annoying part of the whole thing.

I considered using a spare iPhone to host a physical SIM with my US number because that would allow the number to stay bonded with my Apple ID and potentially forward SMS over iCloud, but I decided not to because in my experience the SMS part is too flaky to be relied on.

> but that would require unenrolling my US iMessage number

It nags you but you don't have to agree to remove the number. I routinely replace my SIM card when traveling outside the EU and my iMessage number still works for green-bubble people. I ignore/refuse the phone's occasional suggestions to "update" the number.

> iPhone 12 can only have 1 eSIM enabled at a time. You can do 1 physical + 1 eSIM, but not 2 esims.

IIRC this is a limitation that only applies to iPhone <=12.

I am pretty sure that newer iPhone models all support dual-active eSIM, irrespective of whether or not you have a physical SIM slot model or not.

Good news, with the elimination of the SIM card slot, they fixed this bug and you can have two eSIMs active with no chance of ever getting a physical travel sim to work! /s

Bleh physical sim swapping when travelling is such a pain. I used travel data only esims all through the US, Europe and Egypt. All set up through a single app. I didn’t need to talk to dodgy airport phone shop people a single time in 3 months on the road - which, iPhone limitations aside, I consider a massive win.

(I used the Airalo app. No association. It worked great.)

For the five minutes it takes to get a physical SIM card, I'll take the much cheaper and typically faster service I get with local carriers vs eSIM MVNOs.

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