Using old SIM in new phone

I just ordered an unlocked iPhone SE 3 without a SIM card. My plan was to swap my current card in an original SE to the new phone. Then I remembered that I had already done that once before. That is, the card was originally in an iPhone 5s.

An online search reveals a lot of conflicting information about swapping older SIM cards into newer phones.

Will SIM card from iPhone 5s work in an iPhone 13?

I think I will go to the Verizon store and ask for a new SIM card. Seems simple enough and I don’t mind wating an extra day.


EDIT: added link to relevant Apple discussion

ymmv but a transfer of the SIM card from my iPhone SE2 into my new SE3 last Friday on Consumer Cellular went without a hitch. :smile:

If it’s an SE 3, you can also have Verizon setup an eSIM rather than use a physical SIM. Either way, if you’re interested at all in 5G services, you’ll want a new physical SIM or have an eSIM set up. Older SIMs will only connect to LTE.


The other thing you might consider is using the eSIM–no worry about transferring a physical SIM

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Thanks, @ddmiller and @aforkosh, for the information on SIM and eSIM. That prompted me to do some additional research and I found this article describing the pro/con of both. Ultimately, a user decision on which is most beneficial.

I went to the Verizon store and they attempted to get the eSIM to work. After almost an hour and multiple calls to their tech support they put in a physical SIM. Worked instantly.

Online reports suggest that eSIM almost always works but there are occasional failures that require escalation to get things functional.

Glad you got it working. I had issue once with a user getting new 13 and she went from a 7. The sim in the 7, as I was told by Verizon support, didn’t support 5G so they sent a new sim card (physical one). the old worked till the new one arrived, but no 5G.
With this, I too, have an SE 3 (2022) and called ATT if I needed a new sim, moving from the 8+ to SE. ATT only cared about me buying new plan. So, I used the old sim and phone is ok.
However, unrelated, I am seeing apps hidden. Have you? its like a dozen apps have to be found via Search. Then added to home screen again.

No, not having this problem. I did a full backup via iTunes of the old phone SE2016. Then a restore of that backup to the new SE3. Documents, wallpaper, photos, etc. all transferred. Most apps showed a cloud icon to download from the app store. When done, all apps were visible and working.

The SIM card upgrade took place the next day. They were happy that I had already done the migration.

Interesting. . . I just installed a SIM that has been in use for over 7 years in an iPhone 5S and 6S. My SE3 indicates that 5G is functioning as expected. We have a rural cell tower around 300 yards from our house.

Prior to upgrading I called Consumer Cellular to confirm that I could simply swap the SIM like I’ve done in the past. They told me to go ahead as there is no need to obtain a new SIM. I’m on the ATT network (T-Mobile is the other option with Consumer Cellular.)

This was the first time that I used the Bluetooth data migration option between the 6S and SE3. The entire process took less than 5 minutes. I was happy to forgo connecting the SE3 to my Mac to transfer the data from my recent backup.

All that I know is that Verizon phones with SIMs provisioned before 5G, especially as old as that, will not connect to 5G but instead will connect to LTE when 5G is available. Not sure about AT&T. (Also AT&T is notorious for calling LTE service “5Ge” on status bars when connected to LTE rather than 5G, and did the same thing 10 years ago when LTE was new when they had phones put a label of 4G when they were actually connected to 3G.)

This may not be such a big deal on the new SE, as it can’t get the ultra-fast mmWave 5G anyway.


That’s very good news, and Consumer Cellular deserves all the credit.

A SIM card, at its core, contains the various ID numbers required to look up and use your account information, so the network knows who you are and how to bill your calls.

If Consumer Cellular can use your existing 4G phone on 5G networks, that means their database is reusing the same ID numbers. They just upgraded your account for the new features.

Verizon appears to do things differently. They seem to be assigning a new ID number for the 5G network, which is used alongside (or instead of) the numbers that identify you to the 4G and older networks. Since a 4G SIM doesn’t have a valid ID for the 5G network, it can’t connect to that network.

Why are the two companies different? It’s impossible to know without talking to the engineers at the various companies, but it may simply be because Consumer Cellular doesn’t run their own network, but resells bandwidth on other networks. The SIM card you get from them (I assume) is a Consumer Cellular ID and the Consumer Cellular servers map that ID onto one or more AT&T IDs, which are actually used to place the calls. So if AT&T requires new/additional IDs, Consumer Cellular can just change the mapping in their server.

Could Verizon do something similar? They absolutely could, but they may feel that it isn’t worth the cost of adding the necessary infrastructure vs. just issuing new SIM cards when the network infrastructure gets upgraded every few years.