Treat activation as its own step
An eSIM is a digital SIM rather than a removable card. The phone needs a compatible cellular plan assigned or transferred through the carrier's supported process. Restoring a device backup is not a universal substitute for that activation.
Depending on the carrier and devices, setup may use a built-in transfer flow, a carrier app, a QR code, or carrier assistance. Apple's guidance explicitly makes these methods conditional on carrier support. Do not assume that a process shown for two recent iPhones will also work between every Android phone and iPhone.
Read the carrier's instructions before deleting an existing eSIM. A QR code may not be reusable, and removing the profile is not the same as canceling a plan or creating a replacement. If activation fails, preserve the working setup while asking the carrier what to do next.
Have a connection that does not depend on the move
Arrange reliable Wi-Fi and enough charge for both phones. You may need the old device nearby, its screen unlocked, or access to the carrier account. The exact requirements vary, so complete any software or account preparation the carrier specifies before starting the transfer.
If you have two lines, write down which number belongs to which plan. Labels such as personal and travel are helpful, but verify the actual number and account as well. A phone can store or manage multiple eSIMs without every combination being active simultaneously; check the device's limits rather than guessing from the list.
Avoid changing several things together. A new phone, a new carrier, and an overseas data plan each add their own conditions. If possible, complete and test one change before starting another. This makes support conversations much clearer if a line does not activate.
Check service, then clean up the old device
When the new line appears, test an outgoing call, an incoming call, a text in each direction, and mobile data with Wi-Fi off. Look at the selected data line if the phone has more than one plan. A signal indicator alone does not prove that the number you intended has moved.
Confirm what happened to the old line. In a supported transfer, activating the replacement may deactivate the previous SIM, but the timing and details belong to the carrier's process. Keep both devices until you have a clear result. If the old phone remains the only way to receive a verification code, do not reset it yet.
Record the carrier's activation confirmation and any support reference. Then remove personal data from the old phone through its normal handover procedure. Keeping an obsolete eSIM screenshot is not a useful backup; keeping access to the carrier account and its verified support route is.
