Cheapest 20GB Mobile Plans on Optus
The cheapest 20GB mobile plan on the Optus network is 25GB SIM Only Plan by spintel at $22.00/mo.
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Forward your bill12 Plans — sorted by price
Showing plans with 20–30GB data on the Optus network. Postpaid and prepaid only.
Prices validated: 25 June 2026
| Carrier | Plan | Data | Type | 5G | $/mo | Actions | |
|---|---|---|---|---|---|---|---|
 | 25GB SIM Only Plan | 25GB | Postpaid | Yes | $22.00 | Switch — $25 | |
 | Starter | 29GB | Prepaid | No | $23.90 | Visit yomojo | |
| Starter | 29GB | Prepaid | No | $23.90 | Visit yomojo | |
 | 20GB 5G SIM Plan | 20GB | Postpaid | Yes | $24.00 | Switch — $25 | |
 | 30GB | 30GB | Postpaid | Yes | $24.80 | Switch — $25 | |
| 30GB | 30GB | Postpaid | Yes | $24.80 | Switch — $25 | |
 | 25GB Mobile Plan | 25GB | Postpaid | Yes | $25.00 | Switch — $25 | |
 | Lifestyle Mobile - Starter | 27.5GB | Postpaid | Yes | $25.00 | Switch — $25 | |
 | 22GB Data 28 Days | 22GB | Prepaid | No | $26.79 | Visit coles-mobile | |
 | 25GB Mobile Plan | 25GB | Postpaid | No | $29.90 | Switch — $25 | |
 | 5G Small | 30GB | Postpaid | Yes | $30.00 | Switch — $25 | |
 | 20GB Data | 20GB | Postpaid | No | $45.00 | Switch — $25 |
Bill Hero is an independent comparison service. We are paid by subscribers and concierge fees, not by carriers or retailers.
Frequently Asked Questions
What is the cheapest 20GB mobile plan on the Optus network?▾
25GB SIM Only Plan by spintel at $22.00/mo is currently the cheapest 20GB plan on the Optus network. Prices are updated daily.
Should I choose postpaid or prepaid for a 20GB plan?▾
Postpaid plans typically include handset financing options and are billed monthly. Prepaid plans are pay-as-you-go — better for flexibility and no credit checks. Both are shown in the table above.
How often are mobile plan prices updated?▾
Bill Hero checks mobile plan data daily. All plans shown were validated within the last 24 hours. See the "Prices validated" date above the table for the most recent check.
Can I switch mobile plans without changing my number?▾
Yes. Mobile number portability (MNP) lets you keep your number when switching carriers or networks. The process usually takes 1–2 business days.
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