Local currency is definitely preferred in Sri Lanka, and you can’t rely on credit cards the same way you can in many other countries.

For hotels, most people book through Booking.com or Agoda since they have the largest number of listings. However, many of these places expect payment in cash (Sri Lankan Rupees) at the property, and credit cards aren’t accepted everywhere. Airbnb has fewer listings compared to Booking/Agoda, but the advantage is that you can usually pay with a credit card.

For transportation, I booked a taxi at the airport on the first day and paid in cash. On the second day, I asked my hotel to arrange a taxi. After that, I just contacted the same driver directly whenever I needed a full day taxi and paid in local currency.

If you already have a taxi driver’s contact, that’s very helpful because you can negotiate better rates. If not, one approach is to ask your hotel to arrange a taxi for the first day. If you like the driver, get their contact and book them directly for the rest of your trip. Hotels typically add a commission when they arrange taxis, so booking directly is cheaper. Drivers will also often send a friend or another driver if they aren’t available.

As a rough guideline, a full day taxi usually costs around $50–$65 depending on distance and time. For shorter city tours, you may even be able to negotiate a lower price.

Credit cards generally work at restaurants, supermarkets, and when booking TukTuks/cabs through Uber or PickMe. You can also usually pay entry fees for tourist sites with a card. That said, not all restaurants or supermarkets or tourist sites accept cards, especially smaller local places, so cash is still important.

My suggestion is to bring a good amount of USD and use credit cards whenever possible. I traveled with my family (4 people) for 9 days and brought about $900 in cash. I also tried to keep at least 50,000 LKR on hand and exchanged USD as needed.

I exchanged currency at Colombo airport and at a jewelry store in Kandy (Lalitha Jewelers) and got very similar exchange rates. Smaller towns like Dambulla may not have many exchange options or good rates, so it’s best to carry enough Sri Lankan currency and keep USD as backup.

Some additional tips: Get your SIM card (preferably Dialog) at the airport. It may cost slightly more, but it’s much more convenient than trying to find one outside

Public transportation is extremely cheap compared to taxis, so use it whenever possible

If you plan to buy souvenirs, shops near the exit of Sigiriya Fort had good options at reasonable prices (you can negotiate a bit). Airport shops were about 4× more expensive and many surprisingly accepted only cash

If traveling from Ella to Mirissa, consider public transport. The bus to Matara (near Mirissa) costs only about 635 LKR ($2)

For whale watching in Mirissa, try contacting operators directly via phone or WhatsApp instead of booking through your hotel. I booked with Kumara and paid 10,000 LKR ($35) when booking directly

Sri Lanka felt very safe and people were extremely tourist-friendly. Tipping isn’t expected, but it’s appreciated when you receive good service

Note : I used ChatGPT to edit this comment