Cheapest 80GB Mobile Plans on Optus
The cheapest 80GB mobile plan on the Optus network is 80GB 5G SIM Plan by southern-phone at $34.00/mo.
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Forward your bill18 Plans — sorted by price
Showing plans with 80–120GB data on the Optus network. Postpaid and prepaid only.
Prices validated: 25 June 2026
| Carrier | Plan | Data | Type | 5G | $/mo | Actions | |
|---|---|---|---|---|---|---|---|
 | 80GB 5G SIM Plan | 80GB | Postpaid | Yes | $34.00 | Switch — $25 | |
 | Pro | 105GB | Prepaid | No | $34.90 | Visit yomojo | |
| Pro | 105GB | Prepaid | No | $34.90 | Visit yomojo | |
 | 100GB SIM Only Plan | 100GB | Postpaid | Yes | $35.00 | Switch — $25 | |
 | 80GB Mobile Plan | 80GB | Postpaid | Yes | $40.00 | Switch — $25 | |
 | 100GB | 100GB | Postpaid | Yes | $41.80 | Switch — $25 | |
| 100GB | 100GB | Postpaid | Yes | $41.80 | Switch — $25 | |
 | 120GB 28 Day Plan | 80GB | Prepaid | Yes | $42.86 | Visit amaysim | |
 | Lifestyle Mobile - Plus | 100GB | Postpaid | Yes | $45.00 | Switch — $25 | |
 | 5G Medium | 100GB | Postpaid | Yes | $45.00 | Switch — $25 | |
| 95GB 28 Day Plan | 95GB | Prepaid | Yes | $48.21 | Visit amaysim | |
 | Essential 100gb | 100GB | Postpaid | Yes | $50.00 | Switch — $25 | |
| Essential 100GB | 100GB | Postpaid | Yes | $50.00 | Switch — $25 | |
| 160GB 28 Day Plan | 120GB | Prepaid | Yes | $53.57 | Visit amaysim | |
 | 100GB Mobile Plan | 100GB | Postpaid | No | $54.90 | Switch — $25 | |
| Premium 120GB | 120GB | Postpaid | Yes | $60.00 | Switch — $25 | |
 | 85GB Prepaid Plan | 85GB | Prepaid | Yes | $63.21 | Visit optus | |
 | 80GB Data | 80GB | Postpaid | No | $65.00 | 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 80GB mobile plan on the Optus network?▾
80GB 5G SIM Plan by southern-phone at $34.00/mo is currently the cheapest 80GB plan on the Optus network. Prices are updated daily.
Should I choose postpaid or prepaid for a 80GB 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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