Yes, Optus works in Thailand. On eligible Optus Choice Plus plans you get 5GB of data plus unlimited calls and texts for AUD$5 per day; on standard postpaid plans it’s AUD$10/day for 1GB. A 2-week Bangkok–Chiang Mai–islands trip costs AUD$70–$140 depending on your plan. A Travelren Thailand eSIM for the same trip costs around AUD$13. Here’s the honest break-even, and where Optus roaming can actually compete.
Travelren is an Aussie-built eSIM brand and we sell Thailand plans, so this comparison has stakes. We’ve put real numbers down — including the cases where Optus’s cheaper rate genuinely holds up.
The quick answer
- Optus in Thailand (Choice Plus plan): AUD$5/day — 5GB data plus unlimited calls and texts. This is Optus’s cheapest day-pass tier.
- Optus in Thailand (standard postpaid): AUD$10/day — 1GB data plus unlimited calls and texts.
- Travelren eSIM, 5GB / 30 days for Thailand: approximately AUD$13
- Crossover (Choice Plus, $5/day): roaming is genuinely competitive for trips up to about a week.
- Crossover (standard, $10/day): the eSIM is cheaper from about day 2 onward.
One important note: which rate you get depends on your specific plan and Optus’s current zone classification for Thailand — these classifications shift, so confirm your rate in the My Optus app before you fly. Telstra, for comparison, prices Thailand in a special discounted “Zone 1” tier at just AUD$2.50/day; Optus’s Thailand rate may or may not sit in an equivalent cheap tier on your plan, so don’t assume — check.
How Optus actually works when you land in Thailand
Thailand has three major carriers: AIS, True Corp, and dtac. Optus’s roaming agreements route to AIS, the strongest 5G network in the country — solid coverage in central Bangkok, Phuket, Pattaya, and Chiang Mai’s old city, with 4G LTE everywhere else including Koh Samui, Koh Phangan, and Krabi. Speeds in tourist zones typically run 30–100 Mbps on 5G.
Optus roaming auto-activates on first use and bills only the days you connect — but background syncs and notifications count, so switch off mobile data entirely on hotel-WiFi-only days if you want to skip the charge.
Optus roaming detail for Thailand
- AUD$5/day on Choice Plus plans — 5GB data, unlimited calls + SMS
- AUD$10/day on standard postpaid plans — 1GB data, unlimited calls + SMS
- Charged per 24-hour usage window, only on days you connect to a Thai network
- Confirm your specific Thailand rate in the My Optus app — Optus’s regional zone groupings change and Thailand’s tier isn’t guaranteed to match other Asian destinations
What a Travelren Thailand eSIM costs
Travelren Thailand plans (AUD, approximate, as of 2026):
- 1GB / 7 days: approximately AUD$4.40 — light use on a Bangkok stopover
- 3GB / 30 days: approximately AUD$9 — sweet spot for 1–2 weeks
- 5GB / 30 days: approximately AUD$13 — comfortable for an islands trip with daily content
- 10GB / 30 days: approximately AUD$18 — heavy use, remote work from Chiang Mai
- Unlimited / 30 days: approximately AUD$32 — never count gigabytes on a long circuit
The eSIM routes on the same AIS network Optus roaming uses. Browse the full Thailand eSIM range.
Break-even math
| Trip length | Optus Choice Plus ($5/day) | Optus standard ($10/day) | Travelren 5GB / 30 days | Cheapest option |
|---|---|---|---|---|
| 3 days (Bangkok weekend) | AUD$15 | AUD$30 | AUD$13 | Choice Plus by a small margin; eSIM beats standard |
| 1 week | AUD$35 | AUD$70 | AUD$13 | eSIM saves $22 vs Choice Plus, $57 vs standard |
| 2 weeks (Bangkok + Chiang Mai + islands) | AUD$70 | AUD$140 | AUD$13 | eSIM saves $57 vs Choice Plus, $127 vs standard |
| 3 weeks | AUD$105 | AUD$210 | AUD$18 (10GB) | eSIM saves $87 vs Choice Plus, $192 vs standard |
If you’re on Choice Plus and travelling under a week, Optus’s AUD$5/day with included calls is genuinely close to the eSIM’s value. Past about a week — or on the standard $10/day rate — the flat-rate eSIM pulls clearly ahead.
When Optus roaming is the better call
- You’re on Choice Plus and your trip is under a week — AUD$5/day with 5GB and unlimited calls is solid value with zero setup.
- You make a lot of voice calls — roaming includes unlimited calls; the eSIM is data-only.
- You want zero setup — roaming activates automatically on landing.
- Your phone isn’t eSIM-capable — check our device compatibility page.
When the eSIM is clearly the better call
- Trips longer than about a week — daily roaming costs keep adding up; the eSIM doesn’t.
- You’re on the standard $10/day rate — the gap opens up almost immediately.
- You want more data headroom — Maps, photo uploads, and video calls chew through 1GB/day fast on the standard rate.
- You’re island-hopping on a multi-stop circuit — one eSIM plan covers the whole trip without daily resets.
Will your phone work with an eSIM?
Almost certainly yes if your phone is from the last few years. iPhone XS and newer (2018+), Google Pixel 3+, and Samsung Galaxy S20+ all support eSIM. Australian iPhones keep a physical SIM tray alongside eSIM. See our device compatibility page.
Common questions
How do I check which Optus roaming rate I get in Thailand?
Open the My Optus app, go to your plan details, and check “International Roaming” for Thailand specifically. Don’t assume it matches what you’ve seen for Japan or other Asian destinations — Optus’s zone groupings vary by country and change over time.
Is coverage good on the islands?
Koh Samui, Phuket, and Koh Phangan have solid 4G in the main areas; smaller islands and remote beaches drop to patchy 3G. Both roaming and the eSIM use AIS, so coverage is identical either way — download offline maps before island-hopping.
Will iMessage and WhatsApp still work on data-only?
Yes — both are tied to your Apple ID and phone number, not the network, and work on any data connection exactly as they do at home.
The bottom line
For Thailand, the honest answer depends on your Optus plan and trip length. If you’re on Choice Plus and travelling under a week, AUD$5/day is genuinely solid value. For anything longer — or on the standard $10/day rate — a Travelren eSIM at around AUD$13 for 5GB/30 days wins clearly, on the same AIS network. Check your specific Thailand rate in My Optus first; that one fact decides which way this goes.
See the full Travelren Thailand eSIM range →