Optus Roaming Bolt-on vs eSIM: Which Is Cheaper?

Optus roaming bolt-ons are a convenient but often pricey way to stay connected, typically costing $5 per day for limited data. For most Aussie and Kiwi travellers, an AussieRoam eSIM is the cheaper and more flexible alternative, providing larger data pools and direct access to local networks without the daily 'roaming tax'.

The Real Cost of Convenience: Optus Roaming Explained

If you are an Optus customer in Australia, the temptation to just 'flick a switch' and use your phone as normal is huge. Optus offers a 'Roaming Pass' or 'Bolt-on' for most post-paid customers. In 'Zone 1' countries (which covers most of the popular spots like the UK, USA, Japan, and much of Europe), you are looking at a flat $5 fee every 24 hours. For that $5, you usually get 5GB of data. If you go over that 5GB, another $5 kicks in automatically.

On the surface, $5 sounds like a coffee. But let’s do the math for a standard two-week holiday in Japan (dest:jp). Over 14 days, you are spending $70 just to keep your data running. If you are heading off on a month-long European summer (dest:eu-42), that bill climbs to $150. That is a lot of gelato money gone before you even leave the airport.

What is a Travel eSIM?

A travel eSIM from AussieRoam is a digital SIM card that you download to your phone. It allows you to connect to local networks in your destination without needing a physical piece of plastic. Unlike your home carrier, which 'roams' by routing your data all the way back to Australia and then back to your destination (which causes lag), an eSIM connects you directly to local towers.

It is important to note that these are data-only plans. This means you do not get a local phone number to make traditional calls or send SMS. However, in 2026, most of us are using WhatsApp, Messenger, or FaceTime anyway. You can keep your Aussie SIM active in your phone to receive those important bank 2FA texts while using your AussieRoam eSIM for all your heavy lifting—Google Maps, Instagram, and TikTok.

Optus Bolt-on vs. AussieRoam eSIM: The Comparison

Feature	Optus Roaming Bolt-on	AussieRoam eSIM
Cost Structure	$5 per 24-hour block	One-off payment for a set data amount
Data Limit	5GB per day (resets daily)	Total pool (e.g., 10GB or 20GB) to use as you like
Network Connection	Roaming partner (can be slower)	Local direct networks (high speed)
Phone Number	Keeps your Aussie mobile number	Data only (no local number)
Setup	Automatic or via Optus App	Digital QR code download
Best For	Short trips (1-2 days)	Long trips and heavy data users

Destination Deep Dive: Where You Save the Most

Bali and Indonesia

Bali is the backyard for many Aussies and Kiwis. When you land at Denpasar, you want to be able to order a Grab or Gojek immediately. While Optus works here, the local networks like Telkomsel and XL Axiata are incredibly robust. By using an eSIM, you hook into these local giants. If you are planning a side trip to the islands, check out our Gili Islands Guide: How to Get There from Bali to see why having reliable maps is a lifesaver when navigating boat transfers.

Japan (dest:jp)

Japan is a high-tech wonderland, but its mobile networks can be tricky for roamers. Optus typically partners with one carrier, but if you hit a dead zone in the Tokyo subway, you are stuck. An AussieRoam eSIM often gives you access to premium networks like Softbank or NTT Docomo. Whether you are hunting for the best ramen or following our Osaka Street Food Guide: What to Eat in Dotonbori, you need low-latency data that doesn't drop out when you enter a basement restaurant.

Thailand (dest:th)

Thailand has some of the best mobile infrastructure in Southeast Asia. Using a local eSIM means you get 5G speeds in Bangkok and solid 4G on the beaches of Phuket or Koh Samui. The daily $5 Optus charge feels particularly expensive in a country where a full meal can cost less than your daily roaming fee.

UK and Europe (dest:gb) (dest:eu-42)

For those doing the 'Big Trip' across the UK and the Continent, an eSIM is a no-brainer. Most AussieRoam Europe plans cover 40+ countries. This means you can land in London (dest:gb), take the Eurostar to Paris, and then head to Spain without ever changing settings or paying a new 'daily' fee. Optus roaming can get complicated if you accidentally cross into a 'Zone 2' country where the daily fee jumps significantly or data becomes incredibly restricted.

How Much Data Do You Actually Need?

One of the biggest traps with the Optus $5/day bolt-on is the 'use it or lose it' nature of the 5GB. If you only use 500MB one day to check maps, you still pay $5. If you use 5.1GB the next day because you uploaded a long video, you pay $10.

With an AussieRoam eSIM, you buy a chunk of data—say 10GB or 20GB—and use it over 15 or 30 days.

• Google Maps: 5MB per search.
• Instagram/TikTok: 600MB - 1GB per hour of scrolling.
• WhatsApp Voice Calls: 1MB per minute.
• Netflix (Standard): 1GB per hour.

For most travellers, a 10GB package is plenty for a two-week trip, making the cost-per-gigabyte significantly lower than the Optus daily rate.

Technical Setup: Is Your Phone Ready?

Before you ditch the Optus bolt-on, you need to check if your phone is ready for eSIM technology. Most iPhones from the XR onwards and most Samsung Galaxy S-series from the S20 onwards are good to go.

How to Install

1. Purchase: Buy your eSIM before you leave. You'll get a QR code via email.
2. Scan: Go to your phone's 'Mobile Data' or 'Network' settings and select 'Add eSIM'. Scan the QR code.
3. Label: Call it 'Travel' or 'AussieRoam' so you don't get it mixed up with your home SIM.
4. Activate: When you land in Thailand (dest:th) or Japan (dest:jp), simply turn on the 'Travel' line and ensure 'Data Roaming' is toggled ON for that specific line.

For a more detailed breakdown, we have a guide on setting up your travel data that walks through the process for both iPhone and Android users.

Why Local Networks Beat Roaming Partners

When you use an Optus roaming bolt-on, your phone is essentially a visitor on a foreign network. You are often deprioritised. This means in a crowded place—like a festival in the UK or a busy market in Bangkok—your data might crawl while the locals around you are flying. Because AussieRoam eSIMs use local network profiles, you are treated more like a local subscriber, giving you better 'ping' and more consistent speeds.

The bottom line

If you are only going overseas for 24 hours and need to keep your Australian number active for phone calls, the Optus Roaming Bolt-on is a simple, low-effort choice. However, for any trip longer than a weekend, the 'lazy tax' of $5 a day adds up fast. AussieRoam eSIMs offer more data for less money, better speeds via local networks, and the flexibility to travel across borders without worrying about daily resets. Save your money for the experiences, not the telco bills.