iPhone 12 Using pre-installed "5G" SIM on the new iPhone 12/12 Pro or use existing iPhone X SIM

[jsamuels]

I'm in Italy. When I upgraded to 5G I had to get a new 128k SIM (also known as a 5G SIM). Generally, most current non-5G SIMs are older, 64k varients. The double capacity is for more complex configuration data necessary for 5G. The older SIM will work, but it's not maximized for 5G. The newer SIM provides a better and more con sistent connection and experience.

 

[Lakersfan74]

I reset my 12 just now. I can activate my new phone by using my old phone. Quick start comes up and select activate new phone. Old phone will activate the camera with a circle, on the new phone a blue graphic comes up you place that graphic inside the circle on your old phone sandwiching the phones together for a few minutes. After that you are asked if you want to transfer date from phone to phone or do it using iCloud. Mine says 22 minutes left.

I will call t-mobile to activate using my new card

 

[Paco II]

Generally, most current non-5G SIMs are older, 64k varients.

Is that accurate? 128k cards have been widely available for a very long time.

 

[Thoradin]

I don't understand: why would anyone ever reuse a SIM? When I order a phone, it is to upgrade my line. It comes assigned to my phone number already. I turn it on, it activates, and the old one deactivates. Every one for the last many years. What would be the point of using your old SIM these days?

That’s the normal way to do things in the U.K.
You get a new phone and put in your old SIM card. The only reason you ever use a new one is if there is a change in network capability and your previous one is too old to take advantage, like 5G.
Most network operators tell you to keep the new SIM in a drawer and switch if you ever need to at a later point, for example a lost or stolen phone.

 

[minik]

I’m a little confused too!

I’m still on an iPhone 8 Plus. I’m just setting up my pre-order for Nov 6th with Apple.

I am paying via installments with the Apple Card at 0%, so the phone will be sim unlocked and the same price whether I choose my current carrier (T-Mobile) or not.

If I choose T-mobile it says “Apple will work with your carrier to activate your new phone.” That makes me a little nervous, because we have this really great, unlimited everything plan with T-mobile, and I’m worried they will upgrade us to some inferior and more costly and lan in the process, if I do this.

so I’m tempted to use the sim free option.

BUT, since I’m upgrading to a 5G phone, if I choose the sim free option I will clearly need to go down to T-mobile to get a 5G sim.

I’m unclear though... if I choose T-mobile, does that mean simply that my phone will cone with a 5G sim that is ready to activate to my number on the T-mobile network?

I had the 11 Pro w/much older T-mobile SIM and purchased the 12 Pro with 'activate my iPhone' option. I did a full back up of the 11 Pro on my Mac and plugged in the 12 Pro for restoring. The first screen on the Finder (under macOS Catalina) had my T-mobile number already populated and I needed to type in my last four of SSN. Moment later the SIM inside the 11 Pro was deactivated and activated the R15 SIM came with the 12 Pro. I have the T-mobile One Plus Promo plan and everything remains the same.

 

[lclev]

I’m a little confused too!

I’m still on an iPhone 8 Plus. I’m just setting up my pre-order for Nov 6th with Apple.

I am paying via installments with the Apple Card at 0%, so the phone will be sim unlocked and the same price whether I choose my current carrier (T-Mobile) or not.

If I choose T-mobile it says “Apple will work with your carrier to activate your new phone.” That makes me a little nervous, because we have this really great, unlimited everything plan with T-mobile, and I’m worried they will upgrade us to some inferior and more costly and lan in the process, if I do this.

so I’m tempted to use the sim free option.

BUT, since I’m upgrading to a 5G phone, if I choose the sim free option I will clearly need to go down to T-mobile to get a 5G sim.

I’m unclear though... if I choose T-mobile, does that mean simply that my phone will cone with a 5G sim that is ready to activate to my number on the T-mobile network?

I ordered a 12P from Apple with a new SIM chip from Sprint (T-Mobile). I did not allow Apple to mess with activation. When I got the phone I simply logged into my Sprint Account and did it online - very easy to do. It just asked me to select the phone I wanted to move the number from then enter the IEMI number of my new phone's SIM chip. 15 minutes later I was good to go. I still have my unlimited everything plan and nothing changed. Sprint and T-Mobile have included 5G with all their plans so there is no need to change plans. I have 5G now and no additional activation or 5G charges.

 

[webbuzz]

Specific to AT&T, the SIM card should not matter unless your SIM is quite old. As long as it gets provisioned correctly it should just work. Per AT&T support reply to me asking for clarification:

"The link I sent explained that all you needed was an eligible device and plan to receive our 5G data. The sim cards are there to tell your device know what carrier and signal to use to provide your data. So the sim card itself has no effect on your 5G service. You've done everything you need to do to qualify for our 5G service, no sim card change required. I hope that explains everything."

Correct for AT&T.

However, the newer SIM cards (6818B and 6817B) will be required to take advantage of standalone 5G, which will be deployed next year.

6818B is a 3-in-1 (Standard/Micro/Nano), you cut the form factor that fits your device.
6817B is a Nano-SIM (comes installed in AT&T devices)

 

[Christian 5G]

Just an input as I didn't even know that SIM car mattered until tonight as I really never questioned it! Long story short, I nearly always transferred my old sim to the new iPhone just like what I did with my recent upgrade to Pro from XS.

I called in to tmobile to complain about few issues I've been having in coverage primarily in the fitness center, major street, etc... Their first question was whether I activated the sim that the iPhone 12 Pro came with and I said no, they said that the new SIM MUST be activated in 12 Pro as it has 5G compatibility.

Long story short, after quick activation, the phone seems to be working perfect now in exact same places I have complained in with data speeds 170mbps+ which was at 60 at the same spot I measured just an hour before.

Make sure to activate the 12 Pro with the new SIM card with whichever carrier you are and dont use any old sim cards.