ATM availability in and around Bukit Lawang can be limited compared with larger Indonesian cities. Machines may occasionally be out of service, have limited cash available, or decline an overseas card. Internet and power interruptions can also affect electronic payments.

A practical approach is to withdraw Indonesian rupiah in Medan before travelling to Bukit Lawang. If you are arriving from another part of Sumatra, consider using an ATM in a larger town when you have the opportunity.

Bring more than one bank card if possible and keep them separately. Foreign currency such as euros, U.S. dollars or British pounds is normally easier to exchange in Medan or another larger destination.

The amount depends largely on what your accommodation and tour package already include. Guided jungle treks may include meals, permits, equipment and transport depending on the experience you choose.

Cash is particularly useful for local meals, drinks, snacks, laundry, small souvenirs, tips, motorbike taxis and community-run activities.

For a short stay, carry enough rupiah for normal personal expenses plus a reasonable backup amount. If you are travelling through Sumatra for longer, remember to budget for the days before and after your jungle trek as well.

Keep most of your cash securely at your accommodation and carry only what you expect to need while walking around the village.

Some accommodation providers, tour operators and restaurants may accept card payments or bank transfers, but card acceptance is not universal.

Even when electronic payment is available, temporary connection problems can prevent a transaction from going through. For everyday village spending, cash remains the safest backup.

Before travelling, check whether your bank requires international card usage to be activated. It is also useful to know your daily withdrawal limit and the foreign transaction fees charged by your bank.

There is usually no reason to carry a wallet full of rupiah into the rainforest. Your guide can explain what you need for your specific trek, including meals, equipment and overnight arrangements.

Leave unnecessary valuables at your accommodation whenever possible and carry only a small amount of money for personal needs before or after your trek.

Bringing a reusable water bottle and following the refill advice of your lodge or guide can also reduce unnecessary purchases of single-use plastic bottles. Small choices like these help keep Bukit Lawang and the surrounding rainforest cleaner.

If you are unsure how much cash you will need, ask your accommodation or tour team before travelling from Medan. Your itinerary and included services usually provide the best guide for deciding how much money to prepare.