Mobile Plans With 20GB to 50GB Data

In our database, we're comparing 50 mobile plans offering between 20GB and 50GB of data a month, each including at least some talk time, billed either every 28 days or every 30 days, from 26 providers across the Telstra, Optus and TPG networks (TPG's network also covers Vodafone-branded plans). Prices run from $1 to $74 a month, averaging $28.14 at today's advertised price and $32.36 once you account for plans that revert to a higher regular price. 33 of the 50 plans are genuinely priced with no promo hike, while the other 17 start cheaper as a limited-time offer and step up afterwards. We've split the tables below so you can tell the difference at a glance, and flagged the handful of 28-day plans with a monthly-equivalent figure so they compare fairly against the 30-day majority.

Genuinely priced, no promo hike (33 plans)

Sorted by cost per GB (regular price), lowest first. These plans cost the same now as they will on renewal -- what you see is what you keep paying. Every plan on this page includes some talk time, so there's no separate data-only table. Almost all bill every 30 days; where a plan bills every 28 days instead, we've added its monthly-equivalent price underneath.

Starts cheaper, price increases later (17 plans)

Sorted by current advertised price, lowest first. "Now" is the price you'll pay today; "Then" is the regular price it reverts to once the promo period ends. Cost per GB is calculated on the regular (post-promo) price, since that's what you'll actually be paying long-term.

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Best value by data amount

Best cost-per-GB (regular price) within each data band. "No promo" means the price shown is the ongoing price, not an introductory offer.

A note on billing cycles

39 of the 50 plans on this page bill every 30 days, and 11 bill every 28 days -- there were no plans matching our filter that billed monthly-calendar (e.g. "1st of the month") rather than on a fixed cycle. A 28-day cycle works out to about 7% more billing periods a year than a 30-day cycle, so a plan that looks cheaper by sticker price can actually cost more per month once normalised. For example, felix's 25GB SIM-only Mobile Plan is $12.50 every 28 days -- that's ≈$13.39/month equivalent, not a flat $12.50/month. We've added the monthly-equivalent figure under the price for every 28-day plan in the tables above so you can compare it fairly against the 30-day majority.

Frequently asked questions

Prices and data allowances shown are current in our database as of August 2026 and reflect advertised carrier pricing at time of listing. Where a plan has an introductory promo, we show both the current and regular price so you can see the true long-term cost -- note that a small number of plans step through more than one promotional price before reaching their regular price, and our two-column format shows only the starting and ending points of that curve. Monthly-equivalent figures for 28-day plans are calculated as price × (30 ÷ 28) and are provided for comparison purposes only -- they do not represent an actual monthly billing amount. Plans, prices and inclusions change frequently, and details are entered into our database manually so errors are possible -- we do not guarantee the accuracy of any price, allowance, or other detail shown. Always confirm the final price and all plan information directly with the carrier before signing up.