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Steviejobz

macrumors 68020
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Jun 19, 2010
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SoCal
I want to swap the SIM card from my current iPhone 11 Pro Max into the iPhone 12 Pro I just ordered. However will the SIM cards be compatible? Does AT&T need to "tell" that the device is a 5G compatible phone and not being used in a 4G LTE phone?

I use AT&T.
 
I want to swap the SIM card from my current iPhone 11 Pro Max into the iPhone 12 Pro I just ordered. However will the SIM cards be compatible? Does AT&T need to "tell" that the device is a 5G compatible phone and not being used in a 4G LTE phone?

I use AT&T.

5G access on AT&T is associated with your plan, not your SIM. Your current SIM should work fine unless it happens to be really really old. But main thing is that your plan may not offer 5G. You'll want to check with AT&T.
 
5G access on AT&T is associated with your plan, not your SIM. Your current SIM should work fine unless it happens to be really really old. But main thing is that your plan may not offer 5G. You'll want to check with AT&T.

From what I have been reading, there is in fact a reason to use the new 5G SIM card. Security and privacy features in 5G may not be fully compatible with a 4G SIM card. This is one of the articles I have seen, it seems to explain why 4G SIM cards will "work" but not completely. I have also seen some carriers who basically explain it that a 4G SIM will work on the 5G networks that are in a compatibility mode of 4G/5G, but a true 5G network there will be issues; I have also seen it's an issue of whether it's a new account (where the security kicks in) or an existing account - which also may be why it works for many. I am no expert and much of this is over my head, so read and comment if you like!

 
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Do we even know if the carriers have the special 5G SIM card discussed in this article (Rel 99+ USIM)?

From what I have been reading, there is in fact a reason to use the new 5G SIM card. Security and privacy features in 5G may not be fully compatible with a 4G SIM card. This is one of the articles I have seen, it seems to explain why 4G SIM cards will "work" but not completely. I have also seen some carriers who basically explain it that a 4G SIM will work on the 5G networks that are in a compatibility mode of 4G/5G, but a true 5G network there will be issues; I have also seen it's an issue of whether it's a new account (where the security kicks in) or an existing account - which also may be why it works for many. I am no expert and much of this is over my head, so read and comment if you like!

 
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5G access on AT&T is associated with your plan, not your SIM. Your current SIM should work fine unless it happens to be really really old. But main thing is that your plan may not offer 5G. You'll want to check with AT&T.

There is a 5G SIM Card from AT&T so having the correct plan and SIM Card is the best option to use all the 5G bands, even standalone 5G (no LTE/4G area) with no issues.

Some people have been issues without the 5G SIM Card in their iPhone 12 devices but not everyone. I went to my Corporate AT&T Store today and asked for the "5G SIM Card" and the lady no problem. She went in the back and came out with a blue and white SIM Card holder and it said 5G in huge letters on it. She popped out the nano SIM Card and put it in my phone, did her stuff in the system and I was done.

She said that AT&T uses 3 different SIM Cards and the 5G SIM Card is the latest...interesting.

The SIM Card I got inside my iPhone 11 Pro Max last year was orange and blue, the new 5G SIM Card is white with a blue AT&T globe. I attached the photo (just blocked out my SIM Card number). The SIM Card is $5 (SIM Cards used to be free at Corporate stores) but the rep didn't charge me.


My receipt showed:

Item ID: 6818B (I assume this is the 5G SIM Card SKU)

Description: SIM VAR UICC-H CONSUM



Now I'm ready to order my iPhone 12 Pro Max on Friday.
 

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Not AT&T but Verizon -- I was going to buy unlocked and just sim swap but saw issues with others not getting 5G doing a sim swap, so I sucked it up for the preorder (this Friday) and am going to do the Verizon version so I get a 5G sim. Not thrilled about their BS activation fees, but I figure it's worth the hopefully non-hassle.

My area doesn't have mmWave 5G but I'm hoping to get some better speeds on the "other" 5G like I've seen reports of from others.
 
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I have yet to see any validation that a new "5G" SIM is required. In almost every case the issues came down to provisioning. 5G is working for most people without the need for a new SIM card.
 
Do we even know if the carriers have the special 5G SIM card discussed in this article (Rel 99+ USIM)?
So i took out my daughters iphone 12 sim and it was just white, didnt look any different except color.

op-ATT says you just need to call them up so they can provision your old sim to make it work with 5G.
 
I have yet to see any validation that a new "5G" SIM is required. In almost every case the issues came down to provisioning. 5G is working for most people without the need for a new SIM card.

No one ever said it was required...it was just posted on other websites that some people had issues without the new SIM Card with 5G (at least on AT&T) so it may not be an issue for all carriers.

I decided what the hell, if they have a 5G SIM Card and I can get one, especially for free, then why not. Plus I would rather have the newest SIM Card since I'm sure it was created for a reason (better 5G connection, security, who knows) and I have a 5G plan.



"My colleague Chance used his iPhone 11 Pro Max AT&T SIM in a new iPhone 12 Pro and AT&T said he needs an updated SIM to get 5G service"
 
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I got the 5g sim from the AT&T store by my house for free, and I was inquiring about 5g plans since it’s not available on my grandfathered unlimited plan. The manager was adamant that 5g is not available in our area even though the AT&T map indicates that it is available. He said that’s only the 5Ge (which, of course, is their marketing term for LTE) and that midband isn’t here, either. He dissuaded me from changing my plan for the time being. Refreshing that he was honest with me. I am glad to be seeing 2x to 3x data speed improvements on LTE with the 12 Pro modem.
 
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No one ever said it was required...it was just posted on other websites that some people had issues without the new SIM Card with 5G (at least on AT&T) so it may not be an issue for all carriers.

I decided what the hell, if they have a 5G SIM Card and I can get one, especially for free, then why not. Plus I would rather have the newest SIM Card since I'm sure it was created for a reason (better 5G connection, security, who knows) and I have a 5G plan.



"My colleague Chance used his iPhone 11 Pro Max AT&T SIM in a new iPhone 12 Pro and AT&T said he needs an updated SIM to get 5G service"
I went to my AT&T store this afternoon to pick up the 6818B 5G SIM card, figuring just like @Omega V that it couldn’t hurt to have the latest one (I haven’t gotten a new SIM in a few years, and my 5G plan is set to start in about a week). At first mention of my request, the associate looked at me like I was from Mars. She appeared confused about my request, and said something about all their SIM cards being the same - they are all 5G cards. Then she said they don’t have that card in their store. Finally (and this all happened in the first two minutes of the discussion), she said that no store in our market carries that card.

I persisted, and asked her if she was sure they didn’t carry the 5G SIM card. I reiterated the SKU, and to her credit, she pulled up an inventory of in-store items on her tablet. After a few minutes, she was able to determine that their store did, in fact, have just a few of them left. She seemed doubtful they actually had them, however, and before going into the back to check, she mentioned that another AT&T store at the other end of the mall has them in stock should she be unable to find them in her store. A few minutes later, she emerged with one card...the only one she could find. She provisioned it to my account, and I was off and running. She mentioned that there is normally a $5 charge for the SIM, but without me asking, she waived it.

In the final analysis, I concluded that the associate, who could not have been nicer, simply didn’t have alot of info on this new SIM card. To her credit, she was open-minded enough to check store inventory...that saved me from having to run around to other stores to try to find one.

If anyone else runs into similar difficulties, I’d recommend asking the associate to double-check their store’s inventory (give him or her the 6818B SKU) to confirm none of these cards are in stock. I was very grateful my associate did that.
 
Apple willingly gave me AT&T 5g sim cards with my new "sim free" iPhone 12 pro Max phones. I'm still restoring so i haven't messed with sims yet but you can just get them from Apple if need be.
 
Apple willingly gave me AT&T 5g sim cards with my new "sim free" iPhone 12 pro Max phones. I'm still restoring so i haven't messed with sims yet but you can just get them from Apple if need be.
Yup. They gave me a 5G AT&T SIM at the Apple store this morning. I had to call AT&T to have them activate it.
 
I walked into my local AT&T store last night with my sim-free iPhone 12 Pro Max... they installed the new 5G sim card, and activated it for no charge.
 
I did NOT swap my SIM from my 11 PM into my 12 PM - I activated the 12 PM with the SIM that came in it. I have all the 5G options in the cellular menu. I also upgraded to a 5G plan a few weeks ago.
 
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Just an FYI, my 12 Pro Max came with a 6817B not a 6818B. Not sure what the difference is.
Just form factor

6818B is a 3-in-1 (Standard/Micro/Nano), you cut the form factor that fits your device.
6817B is a Nano-SIM
 
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I got the 5g sim from the AT&T store by my house for free, and I was inquiring about 5g plans since it’s not available on my grandfathered unlimited plan. The manager was adamant that 5g is not available in our area even though the AT&T map indicates that it is available. He said that’s only the 5Ge (which, of course, is their marketing term for LTE) and that midband isn’t here, either. He dissuaded me from changing my plan for the time being. Refreshing that he was honest with me. I am glad to be seeing 2x to 3x data speed improvements on LTE with the 12 Pro modem.

I have 5G in my area.

Should I finally get rid of my old unlimited plan?
 
After a LONG struggle I finally found a 5G SIM (6818B) at my local ST&T store and got them to put it in (for free). Initially it gave me the 5G, 5G-Auto and LTE options but soon went back to only showing 4G and LTE as I DON'T have a 5G plan, and in my area there is not real 5G - only the 5Ge option. But I do notice two differences - one is that my upload speed is 2.9 times as fast as it was with the old SIM, and I have one more bar of signal strength at my house than I used to have. So - for me - it's a worthwhile improvement. Of course the SIM I had put in the 12 Pro was at least 4 years old ...
 
I also popped in my older nano SIM into my 12. I seem to be getting 5G? Service has been about twice as fast as LTE (30Mbps v 14Mbps) on my Xr.

5G really wasn’t my intent on upgrading anyways. I’m just wondering if there’s something I’m missing out on. Maybe one day I’ll head to the store. Only problem is that the AT&T store makes me really anxious. Such a mess.
 
I also popped in my older nano SIM into my 12. I seem to be getting 5G? Service has been about twice as fast as LTE (30Mbps v 14Mbps) on my Xr.

5G really wasn’t my intent on upgrading anyways. I’m just wondering if there’s something I’m missing out on. Maybe one day I’ll head to the store. Only problem is that the AT&T store makes me really anxious. Such a mess.

Until AT&T roles out Standalone 5G, you’re not missing out on anything.
 
On new accounts you absolutely must have the new 5G sim card in the 12 or it will not run. On older accounts, you should still get a new sim with every upgrade because even LTE had several generations of sim tech that improved speed. So upgrading your 5G device to a 5G sim will generally be a good idea. They're designed to be a more efficient card and they are through and through!
 
I went to the AT&T store to get a SIM (I left my phone over an extended weekend in a building I had no access to) and they gave me the old rinky-dink one. Still says I have 5G but who knows; the speeds always seemed the same to me.
 
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