Compare SIM-only plans: how to choose the right one
A SIM-only plan gives you a mobile service without a phone: you bring a phone you already own and put in the new provider's SIM or eSIM. Because you are not paying off a handset, you can usually leave at any time on a month-to-month or prepaid plan, which is why SIM-only is the cheapest and most flexible way to buy a mobile service in Australia.
The trade-off is that nobody checks your phone for you. Before you switch, make sure the phone is unlocked, supports the new network's 4G bands and Voice over LTE, and handles eSIM if you want one. Then compare plans on the network, data allowance, speed cap and what happens when you run out, using each plan's Critical Information Summary.
By Better Rate Mate Editorial Team · Last reviewed
General information only. We don't compare every provider or plan in the market, and we may earn a commission if you sign up through our links.
Work out a SIM-only plan's yearly cost
The headline price hides two things: 28-day recharges are paid 13 times a year, and introductory prices end. Put in one or two plans to see the yearly cost and the cost per GB.
Mobile plan yearly cost calculator
The real yearly cost and cost per GB, counting 13 payments for 28-day recharges. Example figures are filled in; replace them with the figures from each plan's Critical Information Summary.
Plan A
$455
a year, 13 payments
- Average a month
- $37.92
- Data over the year
- 520 GB
- Cost per GB
- $0.88
Plan B
$444
a year, 12 payments
- Average a month
- $37.00
- Data over the year
- 480 GB
- Cost per GB
- $0.93
Plan B costs $11 less over a year. Check the network, speed caps and what happens when the data runs out before you choose.
Counts 52 payments a year for 7-day recharges, 13 for 28-day, 12 for 30-day and monthly, 2 for 6-month and 1 for 12-month plans, with no price changes. Data rollover, banking, add-ons and excess charges are not included. General information only, not a quote.
Prepaid SIM-only and postpaid SIM-only
SIM-only comes in both forms. A prepaid SIM-only plan is paid in advance for a recharge period, commonly 28 or 30 days, or a long-expiry period such as 365 days; our table of 365-day SIM-only plans lists long-expiry prices for the brands we checked. A postpaid SIM-only plan is billed monthly, most often month-to-month, though some providers offer a lower price or bonus data for a 12-month term with an early termination charge.
Moneysmart notes that some SIM-only plans require a minimum 12-month contract. The minimum term and the maximum early termination charge are both in the top section of the Critical Information Summary, so you can see the commitment before you sign. Our prepaid vs postpaid guide covers the differences in detail.
Will my phone work on a new SIM-only plan?
Check three things before you move your number:
- It is unlocked. Phones bought outright from a retailer are usually unlocked, but a phone bought from a carrier may be locked to its network. Telstra, for example, says it does not lock phones on month-to-month plans, but charges a fee to unlock a Pre-Paid phone that has been active for less than two years. TPG, iiNet and Internode note that a phone may need unlocking if it has not been used on the Vodafone network before.
- It supports 4G Voice over LTE (VoLTE). All three networks have closed 3G, so a phone needs VoLTE to make calls, including calls to 000. Text 3 to 3498 to check a phone, a free service the ACMA points to.
- It supports eSIM, if you want one. Most recent flagship phones do; many budget phones still use a physical SIM only. See our eSIM guide.
Which SIM-only plan has the best coverage?
The plan with the best coverage for you is one on the network that works best where you live, work and travel. The brand does not change the towers: an amaysim plan uses Optus's towers, a felix plan uses Vodafone's, and an ALDI plan uses Telstra's wholesale footprint.
Telstra's full network covers the largest area, but most Telstra resellers use the smaller Telstra Wholesale network, so a cheaper Telstra-network plan is not automatically Telstra coverage. In regional areas Optus and Vodafone now share towers. The fairest comparison is the operators' standardised coverage maps, which the ACMA has required since 30 June 2026. Our network pages list every brand on Telstra, Optus and Vodafone.
What to compare on a SIM-only plan
Price and data are the headline, but these are the features that separate two plans with similar headlines:
| Feature | What to look for |
|---|---|
| Network and tier | Which operator's network, and for Telstra resellers whether it is the full network or Telstra Wholesale |
| Data allowance | Enough for your real use; check your phone's usage screen for the last few months |
| Speed cap | Many plans cap speeds at 100, 150 or 250 Mbps; matters most for hotspotting |
| 5G | Included on the plan, not just offered by the brand |
| When data runs out | Excess charges, automatic top-ups, or slowed speed with no extra charge |
| Data rollover or banking | Whether unused data carries over and how long it lasts |
| Recharge or billing period | 28-day plans mean 13 payments a year |
| International calls and roaming | Included countries and minutes, roaming packs and pay-as-you-go roaming rates |
| eSIM and Wi-Fi Calling | Supported on your phone and on the plan |
| Minimum term and exit costs | Month-to-month or fixed term; the maximum early termination charge |
SIM-only options by brand
The plan type, long-expiry options and what happens to unused data differ more between brands than the headline data does. This is what each brand's own pages showed on 2 October 2026:
| Brand | Network | Plan types | Long-expiry option | Unused data | eSIM |
|---|---|---|---|---|---|
| Telstra | Telstra | Postpaid Upfront plans with no lock-in, and prepaid recharges from 7 days to 12 months | 6 and 12-month prepaid recharges | Prepaid 7 and 28-day recharges roll over up to 200GB if you recharge before expiry | Yes |
| Optus | Optus | Postpaid SIM plans with no lock-in contract, and prepaid | Not readable on its site | Not readable on its site | Yes |
| Vodafone | Vodafone | Month-to-month SIM Only plans with no lock-in, and prepaid | Not confirmed on its plans page | Prepaid rolls over up to 300GB per recharge; SIM Only continues at slower speeds once the allowance is used | Yes |
| Boost Mobile | Telstra (full prepaid network) | Prepaid only: 28-day and long-expiry recharges | 6 and 12 months | Some 28-day recharges roll over unused data if you recharge before expiry | Yes |
| ALDI Mobile | Telstra Wholesale | Prepaid 30-day plans, including family plans | None on its plans page | Unlimited data rollover on eligible plans | Yes |
| Everyday Mobile from Woolworths | Telstra Wholesale | Postpaid SIM Only plans, prepaid 30-day and long expiry | 365 days | Data Bank, and you can gift data | Yes |
| amaysim | Optus | 7-day, 28-day and long-expiry SIM plans | Yes | Data banking | Yes |
| Lebara | Vodafone | Prepaid only: 28-day and 365-day | 365 days | Bank up to 500GB while the service is active | Yes, all plans |
| felix | Vodafone | Monthly plans with no lock-in contract | None on its plans page | Unlimited data banking on plans with a data allowance | Yes |
| Kogan Mobile | Vodafone | Prepaid: monthly and 365-day | 365 days | Monthly plans roll over up to 200GB | Yes |
What's included on a SIM-only plan
Most SIM-only plans now share the basics, so the inclusions below are where plans differ. Check each one in the plan's Critical Information Summary:
- Unlimited standard national calls and texts. Usual on current plans: Boost includes unlimited talk and text on all its 28-day and long-expiry plans, and Vodafone's SIM Only plans include unlimited standard national calls and texts. Check MMS and premium numbers in the CIS.
- International calls. Many plans include minutes to listed countries; ALDI Mobile, for example, includes calls and texts to selected international destinations.
- Roaming. Packs, day passes or a daily charge; how each network's works is on our international roaming page.
- Wi-Fi Calling, which carries calls over home Wi-Fi where indoor coverage is poor. Telstra says it works on its Pre-Paid services too; check your phone and plan support it.
- Satellite messaging. Telstra's SIM-only Upfront plans include Telstra Satellite messaging on compatible phones outside mobile coverage, which can't be used to call or text 000.
- What happens to unused data: it may expire, roll over or go into a data bank (see the table above).
Usage alerts and running out of data
The Telecommunications Consumer Protections Code requires providers to send free alerts when you reach 50%, 85% and 100% of your included data or value, no later than 48 hours after you pass each threshold. The alert is your cue to check what the plan does next.
Plans handle running out in one of three ways: they charge for extra data, they add automatic top-ups, or they slow your speed without charging. If you are often over your allowance, a larger plan is usually cheaper than paying for top-ups; if you rarely use half, a smaller plan is. Cancelling automatic top-ups on a plan that has them is worth doing if you want a hard spending limit.
SIM-only or a phone on a plan?
A phone on a plan spreads the handset cost over 12, 24 or 36 months. The ACCC warns that where the handset is on a longer term than a month-to-month service, you will have to pay off the balance before leaving the provider, and Moneysmart points out you do not own the phone until it is paid off. Missing repayments can affect your credit report.
Buying a phone outright, or keeping your current one, and taking a SIM-only plan leaves you free to change plans whenever a better one comes along. It is usually the cheaper path over two years if you can afford the handset, but compare the total: the device repayments plus plan fees against the phone's outright price plus a SIM-only plan at the same data.
How to switch to a SIM-only plan
Sign up with the new provider and ask to keep your number. The new provider starts the port, and before it goes ahead it must confirm you control the number, usually with a one-time code sent to your phone. Keep your old service active until the port completes; the ACMA says a mobile port usually takes about three hours. Then put in the new SIM or install the eSIM. Switching and keeping your number has the full process.
General information only. We don't compare every provider or plan in the market, and we may earn a commission if you sign up through our links.
What to watch for
- Introductory prices and bonus data that end after a few months. Compare the price that applies after the offer.
- 28-day recharges cost 13 payments a year, not 12.
- Automatic top-ups when you run out of data can add up. Check whether the plan charges or just slows down.
- A locked phone or one without VoLTE will not work properly on the new network.
- A remaining device balance with your old provider is payable when you leave.
Common questions
What is a SIM-only plan?
A mobile plan without a phone. You use a phone you already own with the provider's SIM card or eSIM. SIM-only plans can be prepaid or postpaid.
Which SIM-only plan has the best coverage?
One on the network with the best coverage where you are. Telstra's full network covers the largest area, but most Telstra resellers use the smaller Telstra Wholesale network. Check the standardised coverage maps for your addresses before choosing.
Are SIM-only plans month-to-month?
Most postpaid SIM-only plans are month-to-month, but some have a 12-month term with an early termination charge. The minimum term is in the top section of the Critical Information Summary.
Who has the cheapest SIM-only plan?
It changes every few weeks as providers reprice and run introductory offers, and the cheapest plan depends on how much data you need. Compare the yearly cost at your data level, counting 13 payments for 28-day plans and the price after any discount ends.
What is the downside of eSIM?
Moving an eSIM to a new phone takes a step with your provider rather than swapping a card, not every provider supports it on every plan or device, and if your phone breaks you can't quickly move the SIM to another one. Our eSIM guide covers the pros and cons and which providers support it.
Can I keep my number on a SIM-only plan?
Yes. Your new provider ports the number; your old provider must release it even if you owe it money, although you still have to pay what you owe.
Do I need a new phone for a SIM-only plan?
No, as long as your phone is unlocked and supports 4G Voice over LTE. Text 3 to 3498 to check whether a phone will work now that 3G has closed.