How to Set Up Your SIM Card or eSIM with AT&T: A 2026 Step-by-Step Guide

September 14, 2026
How to Set Up Your SIM Card or eSIM with AT&T

Whether you got a physical SIM in the mail, an eSIM activation card, or nothing at all because your new iPhone has no SIM tray — here is the exact path from unboxed to online, with the menu taps for iPhone, Samsung, Pixel and Motorola.

TL;DR — The Honest Quick Answer

  • eSIM is the fast path: download your AT&T line over Wi-Fi in about 5–15 minutes, no card required
  • Physical SIM still works: insert it, power on, and most new lines activate on their own
  • Turn Wireless Account Lock off first — it silently blocks every SIM and eSIM change on the account
  • You’ll need: Wi-Fi, your IMEI and EID (dial *#06#), an unlocked phone, and your myAT&T login
  • Transferring your number? Go to att.com/activatenow before you turn the new phone on
  • Stuck? AT&T’s automated activation line is 866-895-1099, and a rep can push your eSIM over the air
  • Getting a new AT&T line running used to mean a trip to the store and a paperclip. Now most people finish it on the couch. If your phone supports eSIM, you can go from “just opened the box” to making a call in about ten minutes without touching a SIM tray.

    The snags are predictable, though, and almost all of them come from the same three places: an account security setting nobody remembers turning on, a QR code that already got used, or a phone that is still locked to a previous carrier. This guide walks each scenario in order, so you can jump to yours.

    Physical SIM vs eSIM: what’s actually different?

    Both connect to the same AT&T network at the same speeds. There is no coverage or performance difference between them. The only thing that changes is where the “SIM” lives.

    Physical SIM

    The Classic Way
    • A small plastic card that slides into a tray
    • Move it between phones in about ten seconds
    • Works on essentially any phone ever sold
    • Has to be shipped, or picked up in a store
    • Can be lost, bent, or jammed in the tray
    • 5G phones need a 5G-capable SIM to reach 5G
    eSIM
    Digital & Instant
    • Built into the phone, nothing to insert
    • Activates over Wi-Fi, usually in under 15 minutes
    • Hold a second line or a travel plan at the same time
    • Required on US iPhones from the 14 onward — no tray at all
    • Moving it to a new phone takes a transfer, not a swap
    • Re-downloadable free if you delete it by mistake

    Quick comparison: which one fits you?

    FeaturePhysical SIMeSIM
    Setup time1–3 days shipping, then 5 minutes5–15 minutes, start to finish
    Need a QR code?NoSometimes — many iPhones activate without one
    AT&T Wireless (postpaid)YesYes
    AT&T PrepaidYesYes â€” digital eSIM or a mailed activation card
    Moving to a new phoneMove the card, doneTransfer flow or a fresh QR code
    Two lines on one phoneOne per tray slotMultiple profiles on one device
    International travelSwap in a local SIMAdd a travel eSIM beside your AT&T line
    Lost or damagedOrder a replacement and waitRe-download it, free
    Older phonesAny phoneRoughly 2019 and newer
    Best forSwapping phones often, older devices, backupsNew phones, fast activation, dual lines, travel

    Not sure which your phone can take? Dial *#06#. If an EID appears under the IMEI, your phone has eSIM hardware.

    Before you start: the three-minute checklist

    Every item below is something that stops an activation dead if you skip it. Handle them first and the rest takes minutes.

    An unlocked phone. If it came from another carrier, it has to be unlocked first. AT&T’s eSIM will not download onto a locked device, and a physical SIM will show “SIM not supported.”

    Stable Wi-Fi. An eSIM downloads over the internet, and you do not have cellular service yet. Avoid public Wi-Fi with a sign-in page — the profile download often stalls behind those.

    Your IMEI and EID. Dial *#06# and screenshot the result. Both numbers get asked for at some point.

    Wireless Account Lock turned off. This is the single most common reason activations fail on AT&T. Details in the next section.

    Your myAT&T login, or your account PIN if you are on Prepaid. Support cannot help without one of them.

    If you are keeping your number: your account number and transfer PIN from your old carrier, plus the billing zip code.

    Heads up: activate within 14 days

    AT&T asks that new lines and replacement devices be activated within about two weeks of shipment. Leave a SIM sitting in a drawer past that and the order can be cancelled, which means starting over with a new SIM or eSIM.

    The setting that blocks most failed AT&T activations

    AT&T rolled out Wireless Account Lock in 2025 to stop SIM-swap fraud, and it works exactly as advertised — including against you. While it is on, the account cannot change a SIM or eSIM, upgrade a device, transfer a phone, add a line, or move a number. Nothing errors out with a helpful message; the options simply grey out or the activation quietly fails.

    To turn it off, open the AT&T app on a phone that is active on the account, sign in as the primary or secondary user, and find Wireless Account Lock under your profile or account settings. Toggle it off, run your activation, then turn it back on the same day. Everyone on the account gets a text whenever it changes, which is your early warning if someone else flips it.

    One thing worth knowing: AT&T says it will never call or text asking you to turn the lock off. Anyone who does is running the exact scam the feature exists to block. You can read the official description on AT&T’s Wireless Account Lock support page.

    How to activate your AT&T eSIM on iPhone

    If you bought the iPhone from AT&T, the line often installs itself during setup — Apple calls this eSIM Carrier Activation, and you may never see a QR code. If you skipped the prompt or brought your own phone, here is the manual route. Works on iPhone XS and later; menu names below match iOS 26.

    Connect to Wi-Fi, then open Cellular settings

    Go to Settings → Cellular. On a phone with no line yet you will see Set Up Cellular. If you already have a line, tap Add eSIM instead.

    Pick how the line arrives

    iOS offers a few paths: transfer from a nearby iPhone, transfer from an Android phone, use a QR code, or enter details manually. Coming from another iPhone? Transfer is fastest. New to AT&T with an activation card? Choose the QR code option.

    Scan the code AT&T sent you

    Open the QR code on another screen, or use the printed activation card, and scan it. No code to hand? Tap Enter Details Manually and use the SM-DP+ address and activation code from your AT&T email.

    Let it install without touching anything

    You will see “Activating” for anywhere from two to fifteen minutes. Keep Wi-Fi on, keep the screen awake, do not open the App Store to pass the time. This is where impatient tapping causes half the failures.

    Label the line and set your defaults

    iOS asks you to name it (Personal, Work, Travel) and choose which line handles calls, texts and data. If this is your only line, pick it for everything and tap Done.

    Test before you celebrate

    Turn Wi-Fi off. Make a call, send a text, load a web page over cellular. All three working means you are finished.

    New in 2026: Android to iPhone, no carrier call needed

    With iOS 26, Apple added direct eSIM transfer between Android phones and iPhones, and AT&T is one of the supported US carriers. Put both phones side by side on Wi-Fi with Bluetooth on, then on the iPhone tap Settings → Cellular → Add eSIM → Transfer from Android. Your number moves across and the Android line switches off automatically. Apple’s own eSIM setup guide covers the fallback steps if the pairing screen misbehaves.

    How to activate your AT&T eSIM on Samsung Galaxy

    Samsung’s flow is short, but the menu wording shifted with One UI 7 and 8. If a label below does not match, look one level up in Connections.

    Open SIM manager

    On Wi-Fi, go to Settings → Connections → SIM manager. Older builds call it “SIM card manager.”

    Tap Add eSIM

    You will be offered a QR scan, a transfer from another device, or a carrier app. Choose Scan QR code if AT&T sent one.

    Scan or type the activation details

    Point the camera at the code. For manual entry, tap Enter activation code and use the code printed beside the QR on your AT&T activation card.

    Confirm and wait it out

    The profile downloads in roughly three to ten minutes. Do not lock the phone or switch Wi-Fi networks while it runs.

    Switch the line on and pick defaults

    The new AT&T line appears in SIM manager. Toggle it on, then choose which line handles calls, messages and mobile data if you have two.

    How to activate your AT&T eSIM on Pixel and Motorola

    Stock Android puts this under Network & internet rather than Connections. This path covers Pixel 4 and newer, and current Motorola models.

    Open your SIM list

    Go to Settings → Network & internet → SIMs (some builds say “SIMs & mobile network”). Tap + Add SIM or Download new SIM.

    Choose to download a SIM

    When asked whether to transfer from another device or download one, pick Set up an eSIM / Download a SIM instead.

    Scan the AT&T QR code

    Or tap Enter activation code if you only have the text version.

    Confirm the download

    Review the summary screen and tap Download, then Set up. Expect anywhere from 30 seconds to several minutes.

    Turn the line on

    Back in Settings → Network & internet → SIMs, tap the AT&T line and switch Use SIM on.

    How to activate a physical AT&T SIM card

    Two situations, and they are not the same. Doing the second one in the wrong order is what leaves people with a dead phone for an afternoon.

    Scenario 1: new line, new number

    Your SIM ships ready to go. There is barely anything to do.

    Power the phone off completely

    Fully shut down rather than just locking the screen. Inserting a SIM into a running phone is where “no service” loops start.

    Open the tray and seat the SIM

    Use the ejector tool or a paperclip. Gold contacts face down, and the notched corner lines up with the cutout so it only fits one way.

    Scan the AT&T QR code

    Or tap Enter activation code if you only have the text version.

    Send a test text

    Call someone, send a message, load a page with Wi-Fi off. If all three work, you are live.

    Scenario 2: existing AT&T line moving to a new SIM or phone

    Here you have to tell AT&T to move the line before the new SIM will do anything.

    Turn Wireless Account Lock off

    Do this first, from the AT&T app on a phone still on the account. Skipping it is why the next steps fail for so many people.

    Go to AT&T’s activation page

    Open att.com/activations and choose whether you have AT&T Wireless or AT&T Prepaid. If you are transferring a number in from another carrier, use att.com/activatenow before powering on the new phone.

    Enter the IMEI and the SIM’s ICCID

    The IMEI comes from *#06# on the new phone. The ICCID is the long number printed on the SIM card itself or its packaging. For an eSIM, you will give the EID instead.

    Approve the one-time PIN

    AT&T texts or emails a code to confirm the change is really you. Enter it, and the old SIM goes dead as the new one comes alive — usually within a few minutes.

    Restart and re-enable the lock

    Power cycle the phone, confirm calls and data work, then turn Wireless Account Lock back on.

    Activation stuck in a loop?
    AT&T’s automated activation line handles new lines, upgrades and number transfers — and a rep can push an eSIM profile to your phone over the air.
    866-895-1099
    AT&T activation line · call from a second phone if you can

    Moving a line between two of your own phones

    This is the path most people get wrong, because they try to do it from the phone’s settings rather than from their account.

    Move an active AT&T eSIM to a new phone

    Most common request

    2

    phones on Wi-Fi, one page in your account

    You will need a one-time PIN to finish

    • Turn Wireless Account Lock off first, or the flow will stop partway with no clear reason.
    • Go to Bring your own device in your AT&T account and choose the option to change the device used on your line.
    • Sign in when asked and follow the prompts on both phones.
    • Do not delete the eSIM on the old phone until the new one can call, text, and use data.
    Stuck mid-transfer? AT&T care 1-800-331-0500 Read AT&T’s SIM and eSIM swap steps

    AT&T Prepaid

    Same

    eSIM steps, different support path

    Device swaps go through Customer Care

    • Prepaid eSIM activation follows the same download flow as postpaid, from AT&T’s prepaid eSIM page.
    • Moving an active prepaid eSIM between devices is not self-serve — you call it in from a second phone.
    • Prepaid accounts have their own version of the account lock, so check it before a swap.
    Prepaid Customer Care 1-800-901-9878 Open the AT&T Prepaid eSIM guide

    Bringing a phone from another carrier

    IMEI

    decides this before anything else

    The phone must be unlocked first

    • Run your IMEI through AT&T’s compatibility check before you pay for a plan.
    • A phone still on a payment plan with your old carrier will not unlock, and an unlocked-looking eSIM phone can still refuse an AT&T profile.
    • Once it clears, choose the option to add a line or switch to AT&T and download the eSIM at checkout.

    Watches, tablets and laptops

    eSIM

    only — no tray on most of them

    Usually added as a line on your account

    • Cellular smartwatches pair through the phone’s watch app, then add the line to your AT&T account.
    • Tablets and laptops download their own eSIM the same way a phone does.
    • These count as separate lines with their own monthly charges, even when they share your number.
    Same care line as phones 1-800-331-0500 Open AT&T device activation

    Transferring your number to AT&T

    A port-in adds one layer to everything above, and the order matters more than the steps do.

    Start at att.com/activatenow before you turn the new phone on, because AT&T needs to know the line is arriving from somewhere else. You will need the account number and transfer PIN from your current carrier, the billing zip code, and the exact name on that account. A mismatch in any one of those is the usual reason a port sits pending for a day.

    Most transfers finish inside a few hours. Landline numbers and business accounts take longer. During the handoff you may briefly lose service on both phones, which is normal and not a reason to start over.

    Don’t cancel your old service first

    Cancelling releases the number back to the old carrier, and once released it cannot be ported. You lose it permanently. Let the transfer complete — it closes the old line for you — and keep the old SIM for a week in case the port bounces back.

    Troubleshooting: when it doesn’t just work

    “Activation failed” or no service after setup

    Toggle airplane mode on, count to ten, toggle it off. If nothing, restart fully. Still nothing? Delete the eSIM profile and re-add it. That sequence clears the large majority of no-service cases.

    The QR code says invalid or won’t scan

    Activation codes are single-use and they expire. If you already scanned it once — even onto a phone you have since reset — it is spent, and you need a fresh one from AT&T. Also check the code is not cropped at the edges or dimmed by a screen-brightness setting.

    eSIM stuck on “installing” forever

    Almost always the network. Get off public Wi-Fi with a login portal, and off a VPN. Keep the phone unlocked on the activation screen for up to fifteen minutes. If it is still spinning, restart and try once more before calling.

    “SIM not supported” or “SIM not valid”

    Usually a carrier lock from your previous provider. On iPhone check Settings → General → About → Carrier Lock; on Android look for network lock status in About phone. If it is locked, your old carrier has to release it before any AT&T SIM will work.

    Everything greyed out in the AT&T app

    Wireless Account Lock is on. Turn it off from the app on a device already active on the account — the website will not do it for consumer lines.

    Calls and texts work, but no data

    The APN did not populate. Restart first, since it often fixes itself. If not, ask AT&T to push the settings, or check the APN manually under mobile network settings rather than typing in values you found on a forum.

    AT&T Wireless vs AT&T Prepaid: the difference nobody mentions

    Both support eSIM, but they are run as separate systems with separate support lines, and mixing them up wastes an hour.

    AT&T Wireless (postpaid)

    • Activate through the myAT&T app or att.com/activations
    • Wireless Account Lock lives in the app and must be off for changes
    • Support: 800-331-0500

    AT&T Prepaid

    • Choose digital eSIM at checkout, or have an activation card mailed
    • Cards and devices can take two to three business days to arrive
    • Support: 800-901-9878

    One practical note for Prepaid: your first payment has to process before service turns on. If the eSIM installs but nothing works, check that the plan payment actually went through at att.com/myprepaid before you start troubleshooting the phone.

    So which should you actually pick?

    If your phone supports eSIM, use eSIM. It activates faster, cannot be lost, and lets you add a travel line or a second number without opening anything. The honest exceptions: if you rotate one line between several phones, or you keep an older backup phone for emergencies, a physical SIM is genuinely more convenient. And on current US iPhones the choice is already made for you — there is no tray.

    Either way you get identical coverage and identical speeds. Nobody at AT&T is giving eSIM users a better network.

    Still not connected?
    If the app and the automated line have both let you down, a live AT&T rep can look at the line status directly and re-push the profile.
    800-331-0500
    AT&T Wireless customer service · Prepaid customers use 800-901-9878
    Frequently Asked Questions
    How long does AT&T eSIM activation take?

    Usually 5 to 15 minutes. The profile itself downloads in a couple of minutes on good Wi-Fi, and the network needs a few more to register the device. Add a few hours if you are also transferring a number from another carrier.

    Can I use a physical SIM and an eSIM at the same time?

    Yes, on any dual-SIM phone. Plenty of people run AT&T as the eSIM and keep a second carrier or a travel plan on the physical SIM. In settings you choose which line handles calls, which handles data, and whether the phone switches automatically.

    Does AT&T charge to activate an eSIM?

    The eSIM download itself is free, and so is re-downloading one you deleted. Physical SIM cards sometimes carry a small charge depending on how you order them, and activation fees on new lines depend on your plan, not on which type of SIM you pick.

    Why does my iPhone keep asking for a QR code I never received?

    AT&T has not queued an over-the-air activation for that line yet. Rather than cycling through the same screens, call the activation line and ask them to either email a QR code or push the eSIM profile remotely. It takes a rep a few minutes.

    How do I move my AT&T eSIM to a new phone?

    iPhone to iPhone, use Quick Transfer during setup — the phones talk to each other and no QR code is needed. Android to iPhone or iPhone to Android is now supported natively too, on iOS 26 with AT&T as a supported carrier. If either path fails, AT&T can issue a new activation code. Turn Wireless Account Lock off before you try any of it.

    What if I delete my eSIM by accident?

    It is recoverable, but not always by you. Newer Samsung and iPhone models offer a restore option in SIM settings. Otherwise call AT&T for a fresh activation code — free, just slower. This is why it is worth confirming everything works before you erase or trade in an old phone.

    Will my phone from another carrier work on AT&T?

    Only if it is unlocked and AT&T-compatible. Run the IMEI through AT&T’s bring-your-own-device checker before you order anything. If the phone is still locked, your previous carrier has to release it first — see our carrier unlock eligibility guide for what each one requires.

    Do I need a new SIM card for 5G?

    If you are using a physical SIM, yes — an older SIM in a 5G phone can leave you on LTE. eSIM profiles are provisioned current, so this is not an issue there. If your 5G phone is stubbornly showing LTE everywhere, an old SIM is worth ruling out.

    Source of the article

    Disclaimer

    Last updated September 2026. Steps reflect the current myAT&T app, iOS 26 and Android 16 menus; wording may differ slightly on older software. AT&T’s policies, fees and support numbers can change without notice, and we are not affiliated with AT&T — we just want you connected without losing an afternoon to it.