Almost every guest who books an Indonesia liveaboard asks some version of the same question in the week before they fly: what do I do about my phone? It is a fair question with an annoying answer, because the honest version depends on which airport you land at, how long you are staying, and whether the app you bought a data plan from is actually putting you on the network that matters.
The good news is that getting connected for diving in Indonesia is cheap and takes about ten minutes if you do it in the right place. The bad news is that a lot of the advice online is written for someone who lands in Bali and stays in Bali, and our guests fly on to Sorong, Ambon, Ternate, Maumere or Labuan Bajo, where the choices narrow considerably. This is what we tell people who ask, gateway by gateway, along with the two rules that trip up more visitors than anything else.
One network matters, and that decides most of the rest
Indonesia has four national operators worth naming: Telkomsel, Indosat Ooredoo Hutchison, XL Axiata and Smartfren. In Jakarta or Bali you can pick any of them and be perfectly happy. Fly east and that stops being true very quickly.
Telkomsel is the one with real infrastructure in eastern Indonesia. In Raja Ampat it is not merely the best network, it is frequently the only network present at all, and the same broadly applies across Maluku, north Maluku and the smaller islands off Flores. Every other consideration in this article is downstream of that single fact: whatever you buy, make sure the signal it lands on is Telkomsel.
What coverage actually looks like where we sail
Worth being blunt about this, because the marketing language around "nationwide coverage" is close to meaningless once you are on a boat. Coverage in this part of the world clings to towns and inhabited islands, and a dive itinerary spends most of its week deliberately away from both. An independent survey of Raja Ampat published in 2024 measured usable signal within roughly a kilometre of shore-based stations, degrading sharply at the offshore dive sites five to fifteen kilometres out, which matches what we see from the deck.
| Where | Realistic expectation |
|---|---|
| Bali, Jakarta, Makassar | Full 4G or 5G, every operator, no issues |
| Labuan Bajo town and harbour | Solid 4G, all operators in town |
| Komodo park, north and centre | Intermittent Telkomsel, enough for messages near the busier anchorages |
| Komodo park, south | Effectively dark |
| Sorong | City 4G, and 5G at the airport since late 2025 |
| Waisai and Dampier Strait villages | Bars come and go; text messages yes, uploads no |
| Misool, Wayag, the Fam islands | Dark to marginal, and dark for days at a time in the south |
| Ambon, Ternate | Good city coverage |
| Banda Sea, Forgotten Islands | Assume nothing, for most of a week |
Which leads to the point people find hardest to accept: for the actual diving days, the SIM in your phone is not what keeps you online. If staying reachable at sea matters to you, that is a question about the boat rather than the network, and our guide to liveaboard WiFi and Starlink covers what each route can realistically do. A local SIM is for the airports, the transit days, the hotel nights either side, and the hours when you are close enough to a village for your phone to wake up.
So why bother at all?
Three reasons, and none of them is Instagram. Ride-hailing and food delivery apps run on data and are how you get around Indonesian cities. Everything in Indonesian travel logistics happens on WhatsApp, including your transfer driver, your hotel and quite often the boat's shore contact. And if a flight shifts, which on the eastern domestic routes happens more than anyone would like, being contactable is the difference between a solved problem and a missed connection.
Three ways to buy data, and only two of them are the same thing
This is where most people go wrong, and the mistake is understandable because the products look identical in an app store.
The distinction that matters
A physical SIM or an eSIM sold by an Indonesian operator makes you a subscriber on that operator's network. A travel eSIM sold by an international brand does something different: it puts you on a roaming agreement with whichever Indonesian network that brand has a deal with. The logo on the app tells you nothing about the tower your phone attaches to.
In Bali this rarely matters, because every network works and roaming partners are fine. In eastern Indonesia it matters enormously, because if your travel eSIM roams onto a network that has no towers in Raja Ampat, you have bought a data plan that stops working exactly where you were hoping to use it. Roaming handsets also sometimes cling to a weaker partner signal when a stronger one is available, which is the sort of thing you only notice when you are trying to send one message from a village jetty.
So if you want the convenience of an eSIM, and it is genuinely convenient, buy one that either is a Telkomsel product or states plainly which Indonesian network it uses. If the seller will not tell you, that is your answer.
| Option | Good for | Watch out for |
|---|---|---|
| Physical SIM from an operator counter | Best prices, guaranteed network, staff do the paperwork | Queue on arrival; you must swap out your home SIM |
| eSIM from an Indonesian operator | Set up before you fly, keeps your home number active | Needs an eSIM-capable handset that is not carrier-locked |
| Travel eSIM from an international brand | Easiest purchase, no registration on your part | You are roaming; confirm the underlying network is Telkomsel |
What about just roaming on your home plan?
It works, and it is the most expensive way to do this by a wide margin. Some European and North American plans now include reasonable Indonesian roaming, so it is worth checking yours before dismissing it, but the usual arrangement costs many times what a local bundle does and often delivers worse performance for the reason described above. If your trip is short and your plan happens to include Indonesia, fine. Otherwise it is hard to justify when a local package with tens of gigabytes costs less than a cocktail in Labuan Bajo.
Prices, with the usual caveat
Published pricing for tourist packages is genuinely inconsistent, including on the operators' own pages, so treat the following as the shape of the market in 2026 rather than a quotation. Telkomsel's tourist prepaid products sit somewhere in the region of Rp75,000 to Rp180,000 depending on the size of the bundle and its validity, with roughly 15 GB at the bottom of that range and 50 GB near the top. Indosat's tourist range advertises from around Rp100,000 for a similarly large allowance. Airport kiosks tend to sit at the upper end of whatever the going rate is, and a street vendor offering a "tourist package" at four times these numbers is charging a tourist tax rather than a fair price.
Even at the top of the range that is somewhere around ten to twelve US dollars for more data than most people use in a fortnight. It is one of the few travel costs in Indonesia where the difference between the cheap option and the expensive option is not worth optimising, so buy the larger bundle and stop thinking about it.
Running out, and why topping up is harder than it sounds
There is a small catch-22 built into prepaid data that people meet at the worst moment. Topping up a bundle is usually done through the operator's app or a web page, and both of those need a working connection to load. If you burn through your allowance in Sorong on the morning you fly out to the islands, you may find you cannot buy more without borrowing somebody's hotspot.
Two habits avoid it entirely. Buy a bundle comfortably larger than your estimate at the point of purchase, since the marginal cost of the next tier up is trivial. And if you are staying a while, note that pulsa, the local prepaid credit, is sold as vouchers in convenience stores and phone shops everywhere in Indonesia, which is a way of topping up that does not require you to already be online. Minimarket chains in any decent-sized town sell it, and the staff are used to doing it for people.
Worth knowing too that a tourist bundle has a validity window as well as a data allowance, typically somewhere between seven and thirty days. On a two week trip with a week at sea, a seven day package bought on arrival will expire while you are diving and largely unused, which is a small waste but an irritating one. Match the validity to the trip, not to the data.
Buying one: the paperwork, and the rule that catches people out
Two separate pieces of Indonesian regulation apply here, and conflating them is the source of most of the confusion online. One concerns the SIM. The other concerns your handset.
Registering the SIM
Every SIM and eSIM issued by an Indonesian operator has to be registered to an identity document. Indonesian citizens now register with their national identity number plus biometric facial verification, under a ministerial regulation that came into force in early 2026; foreign visitors use a passport or a residence permit instead.
In practice this means cards are sold inactive and switch on after a verified check. What you need in your hand:
- The passport you actually entered Indonesia on, not a copy and not a photo
- Your entry stamp or e-visa, which some counters record and some do not
- Your handset's IMEI number, which you get by dialling *#06#
At an official counter the whole thing takes about five minutes and the staff do it for you. Buying from an unofficial stall that hands you a pre-registered card is a false economy: those cards are registered to somebody else's identity, they get deactivated, and you will discover this somewhere with no signal and no shop. One more limit worth knowing is that a single passport can generally register up to three SIMs, which only matters if you are travelling as a couple and trying to kit out several devices.
The IMEI rule, in plain terms
Indonesia blocks foreign handsets from its networks unless the device is known to the system, a measure aimed at grey-market phone imports rather than at tourists. The practical effect for a visitor splits neatly at ninety days.
If you are in Indonesia for less than ninety days and you buy a tourist package from an official Indonesian operator, you do not need to do anything at customs. The operator handles the device registration on the network side as part of activation, which is precisely what the counter is doing when it asks for your IMEI alongside your passport. This covers virtually every diver reading this.
If you are staying longer than ninety days, you need to register the handset properly with Bea Cukai, the customs authority, either at the airport on arrival or through their online registration. Import duty can apply above a declared device value of roughly USD 500. Skip it and your phone stops working on Indonesian networks at around the ninety day mark, which is a genuinely miserable way to find out about a regulation.
One useful clarification: an international travel eSIM that roams does not make you an Indonesian subscriber, so the registration obligation sits with your home carrier rather than with you. That is a real advantage of the roaming products, and it is the trade you are making against the network-choice problem described earlier.
Gateway by gateway: where to actually do this
Our trips leave from six or seven different ports depending on the season, and they are not equally well served. The general principle is simple: sort your connectivity at the largest airport you pass through, not the smallest one nearest the boat.
Bali (Denpasar) and Jakarta
The easiest place in the country to do this, and where most of our guests should. Both airports have staffed operator counters in the arrivals area, all the major networks are represented, staff deal with foreign passports all day long and the process is quick even after a long flight. If your route runs through Bali or Jakarta, buy there. You will get better prices, more choice and someone who can troubleshoot in English if your phone objects.
The one thing to do before you leave the terminal is test it. Turn data on, load something, send a message. Fixing a problem at the counter you are still standing next to takes two minutes; discovering it in Sorong takes a day.
Labuan Bajo, for Komodo
Komodo Airport has kiosks near the baggage area selling local SIMs, and Telkomsel has had a service presence around the town and marina. It is workable, but the selection is thin and the staff are not necessarily set up for foreign registration, so it can be slower than you expect. Buy in Bali if you are connecting through it. Our guide on getting to Labuan Bajo covers the flight routing itself.
Sorong, for Raja Ampat
Domine Eduard Osok airport has booths just outside arrivals and the city has proper operator stores, so it is more capable than its size suggests. Telkomsel switched on 5G at the airport in late 2025, which is a nice surprise for a city most visitors treat as a transit stop.
The important bit is timing. Activate and test your data in Sorong, before you board. Signal in the islands is not strong or stable enough to run an activation flow that expects a working connection, and there is no shop in Waisai that will sort out a failed setup for you. This is the single most common connectivity mistake we see on Raja Ampat departures, and it is entirely avoidable.
Ambon and Ternate, for the Banda Sea and Halmahera
Both are provincial capitals with decent city coverage and operator stores in town, but the airports are modest and you should not count on a well-staffed counter. If you are routing through Jakarta or Makassar to reach them, buy on the way through. If you overnight in Ambon before a Banda crossing, which many guests do, a store in town is a twenty minute errand and worth doing on arrival rather than on departure morning.
These are also the routes where the SIM matters least once you sail, because a Banda Sea or Forgotten Islands crossing puts you out of range of everything for days.
Maumere and the smaller ports
Maumere works as an embarkation point for Alor and Banda itineraries and the town has phone shops, but it is small and the airport is not a place to rely on. Treat it the way you would treat any small regional airport: arrive already connected. The same applies to Kaimana and Manokwari on the Triton Bay and Cenderawasih routes, where the sensible plan is to have everything working before you get on the domestic flight. Our Maumere guide has more on the town itself.
The general rule
Buy at the biggest airport on your itinerary, register it properly with your passport, test it before you leave the building, and top up the bundle to something larger than you think you need. Every part of this gets harder the further east you go, and none of it gets cheaper.
The night before you board
Once the boat leaves the harbour, whatever you did not sort out ashore stays unsorted for the length of the trip. This is a short list and it takes about twenty minutes.
Two-factor authentication is the real trap
This one catches competent, organised people, and it is worth more attention than the SIM itself.
If you have swapped your home SIM for an Indonesian one, any service that sends a verification code by SMS to your home number can no longer reach you. That includes a lot of banking, some airline accounts and, awkwardly, some email providers when they notice you logging in from a new country. People discover this when they try to check in for a flight home from a hotel in Sorong and cannot get past the security step.
The fixes are all easy and all need doing before you travel:
- Move your important accounts to an authenticator app rather than SMS codes
- If your phone takes two SIMs, or one SIM and one eSIM, keep your home number active for receiving texts and use the Indonesian plan for data
- Log in to anything you might need, from the country you are in, before you lose access to it
- Write down or store offline any recovery codes your accounts offer
Download it while you still can
Offline maps for the region, your boarding passes, your dive insurance details, your hotel confirmations, whatever you plan to read or watch, and the music. Streaming anything at sea is not realistic and, on boats with satellite internet, it is the one use everybody is asked not to make of a shared connection.
Screenshots beat apps for anything critical, because a screenshot does not need to phone home to display itself. Boarding passes that live inside an airline app have a habit of refusing to load precisely when you have no data.
Tell people you will be dark
Worth a message to whoever would worry. Say the dates, say you will be out of range rather than ignoring them, and give them the operator's office contact for genuine emergencies, which for us is the shore office rather than the boat. Every reputable liveaboard carries satellite communications for emergencies and safety traffic, and that channel exists for medical and operational situations rather than for reassuring relatives, but the shore office can always reach the vessel if something genuinely matters.
The short version
Buy data that runs on Telkomsel. Register it at an official counter with the passport you entered on. Do it at the biggest airport you pass through, and test it before you walk away. Get your two-factor codes off SMS. Download everything you will want. Then put the phone in the cabin and assume you are offline until the boat comes back within sight of a village, because that is very close to the truth, and on the better weeks it is the point.
