SIM cards and internet in Indonesia: what to buy and where

Indonesian mobile data is among the cheapest in Southeast Asia. A prepaid card with 20 to 50 gigabytes costs less than a restaurant dinner, and it works on most islands. For maps, ride-hailing, translation and bookings, a local number is more useful than roaming, which is why almost every traveller buys one at the airport.

The process is slightly bureaucratic. Since 2017, every prepaid SIM must be registered to a passport or national ID, and phones bought outside Indonesia must have their IMEI registered to avoid being blocked after a grace period. Neither step is difficult, but both require the passport you travelled on.

Which operator to choose

Telkomsel has the widest coverage, including remote parts of Papua, Maluku and Kalimantan where the competitors thin out. It is also the most expensive. Indosat Ooredoo, XL Axiata with its Axis brand, and Tri offer cheaper packages and are fine in Java, Bali, Sumatra and the main tourist islands.

If your trip stays on the beaten track, XL or Tri will save money. If you are going to Raja Ampat, the Banda Islands, Sumba or the Papuan interior, Telkomsel is the safer choice. Coverage maps are optimistic; ask at the guesthouse which network the staff use.

• Telkomsel: widest coverage, highest price
• XL and Axis: good value in tourist areas
• Tri: cheap data, urban coverage
• Indosat: solid in Java and Sumatra

Buying and registering

Buy at an official operator shop, a convenience store such as Indomaret or Alfamart, or the airport counter. Bring your passport: the seller will scan it and register the number, which takes a few minutes. Airport counters are more expensive but convenient, and they will set the APN and activate the package for you.

Avoid buying from a street vendor without registration. The card may work for a day and then be blocked, and you have no recourse. If a seller asks for a photocopy of your passport and promises to register it later, walk away.

Airport counters are the easiest option if you arrive late: the staff speak some English, the package is activated before you leave, and you can test it in the terminal. The premium is small compared with the cost of a taxi to a shop that turns out to be closed.

The IMEI rule for foreign phones

Indonesia blocks phones whose IMEI is not registered, but the rule is softer than it sounds. A foreign phone used with an Indonesian SIM gets a 90-day grace period; after that, service can be suspended unless the IMEI was registered at customs on arrival or through the operator. In practice, most short-stay visitors are unaffected.

For a long stay, register the IMEI at the airport customs desk, where the phone's value may attract a small duty, or use the operator's registration service. Bringing a second unlocked phone as a backup is a pragmatic alternative, and an eSIM avoids the physical card but not the IMEI rule.

Data packages and top-ups

Prepaid packages are sold by quota and validity: 10 GB for 30 days, 30 GB for 30 days, or a cheaper daily package. Prices vary by operator and promotion, but IDR 50,000 to 150,000 covers most visitors for two weeks. Top up at a convenience store, through the operator app, or with a voucher code.

Watch the distinction between quota types. Some packages include only daytime data, some exclude streaming, and some treat video apps separately. Read the fine print, or ask the seller to activate a package that covers everything you need.

If you run out, top-ups are quick: buy a voucher at any convenience store, enter the code in the operator app, or ask the shop staff to do it. Keep the original SIM packaging until you leave the country, because the phone number and the registration details are printed there.

eSIM and roaming alternatives

Telkomsel, XL and Indosat sell eSIMs, and international eSIM providers resell Indonesian data at a markup. An eSIM avoids the queue and the physical card, and it is the easiest option if your phone supports it. The catch is that you may not get an Indonesian phone number, which some apps require for registration.

Roaming with your home SIM works but is expensive, and some networks throttle video. If you only need maps and messages for a week, roaming is fine. For a longer trip, a local card pays for itself in the first day.

Coverage where it matters

Bali, Java, Lombok and the main parts of Sumatra have good 4G almost everywhere, including most tourist areas. Nusa Penida and the Gilis are patchy in the interior. Flores has signal in towns and along the main road, with dead zones in the mountains. Raja Ampat has coverage around Waisai and Misool's resorts, but not on the outer islands.

Papua is the hardest region: Jayapura and Wamena work, the Baliem Valley has spots, and the interior has none. Download offline maps and bookings before you leave the last town. A power bank matters as much as the SIM, because navigation drains a phone faster than a day of photos.

Practical checklist

Bring an unlocked phone, buy a card at the airport or a convenience store, register it with your passport, and ask for a package that includes everything. Save the operator app and your number, and keep the physical card in case you need it in another phone.

• Unlocked phone, passport for registration
• Telkomsel for remote islands, XL or Tri for value
• 20-50 GB is plenty for two weeks
• Download offline maps before remote travel
• Keep a power bank in your day bag

Questions people actually ask

Can I buy an Indonesian SIM card with a foreign passport?

Yes. Registration with a passport is the normal process and takes a few minutes at an official shop or airport counter.

Which Indonesian network has the best coverage?

Telkomsel has the widest coverage, especially in Papua, Maluku and remote islands. XL, Tri and Indosat are cheaper and fine in Java, Bali and Sumatra.

Will my foreign phone work in Indonesia?

Yes, with a 90-day grace period before the IMEI rule can suspend service. For a long stay, register the IMEI at customs or through the operator.

How much data do I need for two weeks?

Twenty to fifty gigabytes is comfortable if you use maps, messaging and the occasional video. Light users can manage with ten gigabytes plus offline maps.