Indonesia’s three major carriers — Telkomsel, XL Axiata, and Indosat Ooredoo — have good coverage in Bali and Java but variable reach across the outer islands. Telkomsel has the widest national footprint by a significant margin and is the network to prioritise if your itinerary extends beyond Bali to Lombok, Flores, Sulawesi, or Kalimantan. For a Bali-only or Bali-plus-Java trip, any of the main networks will serve you.

Indonesia does have registration requirements for local SIM cards: foreigners are supposed to register with a passport number. In practice, tourist SIMs sold at Denpasar Airport’s arrival kiosks (Telkomsel and XL Axiata both operate counters) process the registration at point of sale without additional friction. SIM prices are very low — IDR 50,000-150,000 (£2.50-£7.50) for a 30-day plan with 10-30GB is typical. This is one of the destinations where a local SIM is genuinely competitive on price and straightforward to purchase, which makes the case for eSIM more about travel profile than cost.

The eSIM case for Indonesia is strongest for travellers who: arrive at Denpasar late and don’t want to navigate a counter queue jet-lagged; need their home number active for authentication codes throughout the trip; or are on a multi-country Asia circuit (Bali after Singapore or Japan) where swapping physical SIMs is inconvenient. For those travellers, eSIM is the right call.

Yesim covers Indonesia on the Telkomsel network — the correct choice for anyone venturing beyond Bali. Telkomsel’s coverage reaches Lombok’s Rinjani base camp areas, the Komodo Island dock villages in Flores, and the main resort areas of Gili Trawangan. Pricing runs $8-$15 for 7 days/3GB and $20-$28 for 30 days/10GB. Tethering is supported.

Airalo covers Indonesia at a slightly lower price point: $5-$10 for 7 days/2GB, using either Telkomsel or XL Axiata depending on the specific plan tier. Airalo’s regional Asia eSIM is worth checking for multi-country circuits. Saily covers Indonesia with Telkomsel-equivalent roaming and is clean for the NordVPN-ecosystem user.

Specific coverage notes: Ubud and the southern Bali resort coast (Seminyak, Canggu, Kuta, Nusa Dua) have excellent coverage on all major networks. The hill roads north of Ubud toward Kintamani and Gunung Batur have functional but sometimes 3G-only signal in the volcanic interior. The Gili Islands (Gili Trawangan, Gili Meno, Gili Air) have Telkomsel coverage in the village areas; the island interiors and beaches away from the village are 3G at best. Nusa Penida (a thirty-minute fast boat from Sanur) has coverage in Toyapakeh village but limited signal at the clifftop viewpoints like Kelingking Beach — download navigation there before departure.

For Flores and the Komodo National Park, Labuan Bajo town has Telkomsel 4G. The island interiors of Komodo and Rinca, where the dragon treks occur, have no mobile coverage — this is normal for a national park and doesn’t require a better eSIM. Sulawesi’s Toraja highlands and Komodo’s dive sites follow similar patterns: coverage in the access towns, none in the wilderness.