Optus prepaid roaming packs vs a travel eSIM, priced out

What the packs actually are

From Optus’s prepaid roaming page:

All of them are Zone 1 only.

That $45 pack is worth pausing on. 10GB over 28 days for $45 is better than anything Telstra or Vodafone offer a prepaid customer, and better than every MVNO roaming pack in Australia except on a strict dollars per gigabyte basis. If you are an Optus prepaid customer taking a month long trip to a Zone 1 destination, that is a good product and you should probably just buy it.

The destination count, and a number that does not add up

Optus’s prepaid page carries this headline:

“Roam in over 150+ destinations. Staying connected when traveling is made easy with Optus.”

We counted the list published underneath it. It contains 125 destinations plus in-flight roaming, not 150 plus. The 153 destination figure belongs to the postpaid Zone 1 list on a different page.

That is not a reason to distrust the product, but it is a reason to check the list rather than the banner. Twenty eight destinations that a postpaid Optus customer can roam in are not available to a prepaid one.

Eligibility, which is stricter than it looks

Optus’s terms are specific:

“International Roaming Add-ons: Available on Optus Flex Plus, Optus Flex Plus Casual, Optus Flex Plus Traveller, Optus Prepaid Epic Data or Optus Prepaid Epic Value. Must have an active unexpired recharge at the time of purchase (excluded Optus Flex Plus Traveller). Activation of service must be completed in Australia.”

Three things there catch people.

Your plan has to be one of the five named. If you are on an older Optus prepaid product, the add-ons are not available to you.

You need an active unexpired recharge, except on Flex Plus Traveller. So a prepaid service that has lapsed cannot buy a roaming pack, which is exactly the state a lot of infrequently used travel handsets are in.

The SIM must have been activated in Australia. Buying an Optus prepaid SIM at an overseas airport and expecting to add roaming will not work.

The one day pack expires at Australian midnight

The $5 add-on is not 24 hours. From Optus’s terms:

“1 day add-on expires at 11.59pm on day following purchase.”

So it runs to the end of the following Australian day, not for a rolling 24 hours from purchase. Buy it late in the Australian evening and you get less than you expect. Buy it early in the Australian morning and you get closer to two calendar days.

This is the opposite of how Optus’s postpaid Daily Roaming works, which is a genuine rolling 24 hours from first use. Same company, two different clocks.

The one genuinely generous mechanic

Optus rolls unused inclusions over if you buy again before expiry, and the caps are enormous:

“Unused add-on inclusions will rollover up to a maximum of 7000 minutes, 7000 SMS and 70GB data if you purchase another International Roaming Add-on prior to expiry, inclusions accumulated over those amounts will be forfeited.”

70GB of rollover is not a limit anyone will hit, so in practice a regular traveller who tops up before expiry keeps everything. That is better than Telstra prepaid, which forfeits on expiry, and better than Belong, which forfeits the old pack when you buy a new one.

One ordering note from the same terms: “Any available Travel Credit will be used up before International Roaming inclusions.”

Is there pay as you go on Optus prepaid?

Yes, on one plan, which is different from Telstra.

“To access roaming on all Prepaid plans (excluding Optus Prepaid Daily), you’ll need to purchase an add-on at an additional cost… On Optus Prepaid Daily, roaming add-ons are not available and roaming charges will be deducted from any available Credit balance.”

On Optus Prepaid Daily the rate is $0.50 per MB in Zone 1, deducted from your credit balance. That is $500 a gigabyte, so it is not a plan, it is an accident. It also stops when your credit runs out rather than accruing a debt, so it is a soft stop rather than a bill.

When the Optus prepaid packs are the better buy

Month long trips to Zone 1. The $45 pack at 10GB over 28 days is strong, and it includes 100 minutes and 100 texts on your own number. We do not offer calls at all.

Multi trip travellers. The $75 pack runs 186 days and rolls over if you top up. If you take three trips in six months, that is a genuinely good structure and nothing we sell competes with it.

When you need your number to take calls. A travel eSIM is data only.

Short trips where 1GB is enough. $5 for 1GB plus 25 minutes and 50 texts is fine for a couple of days.

When a travel eSIM makes more sense

Your destination is not in Optus Zone 1. Check the list of 125, not the banner.

You are not on one of the five eligible plans, or your recharge has lapsed.

You want the price fixed and the data working before you land.

Heavier data use. Here is the arithmetic on the destinations Australians actually go to, using our prices from 17 August 2026:

We are cheaper on every row, and Optus includes calls and texts on your own number on every row. Those are not the same product and you should weigh the minutes at whatever they are worth to you.

Running both

Because receiving a text does not trigger any charge, you can keep your Optus prepaid number alive for bank codes while a travel eSIM carries the data, and simply not buy an add-on. Without an add-on there is nothing to charge against, unless you are on Optus Prepaid Daily, where credit can be consumed at $0.50 per MB. On that plan specifically, turn data roaming off for the Optus line.

Buy the eSIM before you fly, check your phone is compatible and unlocked, install it on airport wifi after you land, and set it as your mobile data line with data roaming on for that line only.

The verdict

Buy the Optus prepaid add-on if you are on an eligible plan, your destination is in Zone 1, and either your trip is around a month (the $45 pack) or you travel several times a year (the $75 pack and the rollover).

Buy a travel eSIM if your destination is outside Zone 1, your plan or recharge status makes you ineligible, or you want more data for less money and do not need the minutes.

If you are on Optus postpaid rather than prepaid, the product is completely different and considerably better. We have written it up in how Optus daily roaming switches itself on.

Questions people actually ask

Can I get Optus Daily Roaming on prepaid?

No. The $5 for 5GB product is postpaid only. Prepaid customers buy separate add-ons.

Which prepaid plans can buy roaming add-ons?

Optus Flex Plus, Flex Plus Casual, Flex Plus Traveller, Prepaid Epic Data and Prepaid Epic Value. You also need an active unexpired recharge, except on Flex Plus Traveller.

How long does the $5 add-on actually last?

Until 11.59pm on the day following purchase, in Australian time. It is not a rolling 24 hours, so buying late in the Australian evening gives you less.

Do unused inclusions roll over?

Yes, if you buy another add-on before the current one expires. The caps are 7000 minutes, 7000 SMS and 70GB, which nobody will reach.

How many destinations do the prepaid packs cover?

Optus’s page says “over 150+”, but the list published underneath contains 125 destinations plus in-flight. Check the list.

What happens if I do not buy an add-on?

On most prepaid plans, nothing. On Optus Prepaid Daily, roaming charges come out of your credit balance at $0.50 per MB in Zone 1.

Can I buy an add-on while overseas?

Yes, through the My Optus app, which needs wifi or data. Set it up before you fly.

Sources

Optus prepaid figures, terms, eligibility and destination list retrieved 17 August 2026 from Optus Prepaid International Roaming, Optus International Roaming explained and Optus prepaid roaming rates. Our prices from our own product pages, same date.

Written by Lachlan, who runs The SIM Shop from Brisbane and answers the support email himself.