What is an eSIM?
An eSIM (embedded SIM) is a digital SIM card built into the phone itself. Instead of pushing a plastic chip into a tray, you download the plan — normally by scanning a QR code — and the phone treats it like any other line. Here is what matters if you are flying to Bali.
How an eSIM works
A phone with eSIM support has a small permanent chip that can hold one or more mobile plans. When you buy a plan you get an activation code; in the Bali eSIM app it is simply there, in the order. The phone writes the plan onto the chip and from that point it behaves like a normal SIM card.
Because the eSIM sits beside your physical SIM, the phone can run both at once: your own number stays reachable while the eSIM carries data on an Indonesian network.
eSIM or a SIM card bought on arrival
A local SIM in Indonesia means finding the counter, handing over your passport for the mandatory registration, and swapping a chip small enough to lose in a beach bag. An eSIM arrives instantly, installs in about two minutes, and cannot be misplaced.
The trade-off is worth stating plainly: a local SIM gives you an Indonesian phone number, which an eSIM data plan does not. If all you need is internet, the eSIM wins on time; if you are settling in for months and want a local number for local apps, buy the local SIM.
Which phones support eSIM?
iPhone XS and newer, Samsung Galaxy S20 and newer, Google Pixel 3 and newer, and most recent mid-range and flagship Android phones. There are regional exceptions — some models sold in a few markets ship without eSIM — so it is worth a look before you buy a plan.
Why it suits a trip like this
The first day of a Bali trip is the jet-lagged one, and it is a poor day to spend in a queue. An eSIM removes the two slow steps: no roaming statement waiting for you at home, and no counter in arrivals when you would rather be in the taxi watching the rice fields go by.
You install the plan before leaving, and when the wheels touch down at Denpasar the phone finds a network on its own. Your messaging apps, your banking app and your number carry on as usual — on Lombok and the Gilis too, since the plan covers all of Indonesia.
Is an eSIM secure?
At least as secure as a plastic SIM. The plan lives in a dedicated secure chip, it cannot be lifted out of a lost card, and installing or removing it requires the unlocked phone in your hand.