Best SIM only mobile plans

Finding the right ‘SIM only’ mobile plan should be a fairly straight-forward process. However, with a plethora of SIM only vendors, mobile networks, short-term promotional rates, variables, extras and conditions to sift through, things can get confusing.

GadgetGuy’s Guide to SIM only mobile plans will help you understand the difference, as well as what to look for. We’ve also provided our recommended SIM only plans to help you ‘sort the wheat from the chaff’. If any of the terms we use don’t mean a lot there is an explainer at the end of this guide.

SIM only mobile plans

So what do we mean by ‘SIM only’ plans? These are mobile plans that include an allocation of voice and data, where you ‘pre-pay’, normally by the month. There are no lock-in contracts and you can choose a budget that you are comfortable with.

Keep in mind that SIM only plans do not include the cost of a new mobile phone, so you’ll need to bring your own. You also need to have a physical SIM for your phone once you choose a plan. This can either be purchased online and posted to you, or go to Coles, Woolies or major CE retailers and pick one up. There is normally an initial cost for the SIM ranging from $2-15. It may be called a ‘starter pack’ and have bonus voice and data.

Your SIM will be associated with a mobile number, which will remain the same for as long as you use and ‘recharge’ the SIM month to month. The SIM will access one of the three major carrier networks: Telstra, Optus and Vodafone. However, many competitive SIM only plans are sold by Mobile Virtual Network Operator (MVNOs) who resell various ‘bits’ (capabilities) of the major telco’s networks.


Mobile Virtual Network Operators usually offer pre-paid monthly roll-over plans with no lock in contracts. If you do the sums, you will probably find that buying a handset outright using an MVNO for a specified monthly data amount and unlimited calls and text within Australia is a much better deal than ‘post-paid’ mobile plan offers. If you have an existing mobile number, you will be given a choice to keep your current number when you activate the new plan. Activation is usually quick and painless.

VoLTE and Wi-Fi Calling

Special calling features, called VoLTE and Wi-Fi Calling are not as widespread as you might be led to believe. This could well be the most important aspect of which vendor you choose, if you want access to these features.

VoLTE (Voice-Over-LTE) means your voice calls can use the current 4G LTE mobile network, and not fall back to the slower, and older 3G network. Essentially, this means that your calls will be clearer. Wi-Fi Calling is part of VoLTE and seamlessly swaps between the Carrier network to your home/office/coffeeshop Wi-Fi network (and vice versa) for calls and SMS. This feature can help save mobile data as it uses Wi-Fi where it can.

Telstra provides these calling options in most city/suburban areas but not across the entire network. It only allows Boost Mobile to offer it. Optus is rolling it out but at present only allows Moose and Spintel to access it. Vodafone is rolling it out too but coverage is very limited, and as far as we know, no MVNO has access to it.


At present no MVNO has 5G access, as it’s only available through premium ‘post-paid’ plans. Also, Telstra, Optus, and Vodafone have very limited coverage. In Telstra’s case, its 5G starts at $65/80GB per month. We think 5G should not a deciding factor should you want an inexpensive SIM only plan. 4G is perfectly adequate for most uses, and it will be around for many years. Interestingly, Telcos are starting to re-allocate 3G bands to help 5G coverage so don’t expect 3G to be around for too much longer.

Coverage is really important too

Telstra and Optus are neck-and-neck when it comes to the most Australian coverage. Vodafone is more for capital cities/suburbs and some larger regional cities. The main thing here is to see what signal strength you get with each network. You can measure signal strength in -dBm (lower the better) with a free Android app called Network cell Info. It’s worth trying this where you work, live and play. Take the carrier coverage maps with a big grain of salt – they are based on ‘models’ not real reception.

SIM Only mobile March 2021
This amazing free app will tell you the LTE Band, signal strength (lower is better) and so much more like if it finds adjacent towers (good), real download and upload speeds and even identify the nearest tower on a map.

How much data will you need?

The best advice is to check your exisitng plan’s data consumption to see what you have been using.  GadgetGuy has some great advice here including a tool to help you calculate data needs. Here’s a quick summary:

  • Occasional users who regard a smartphone as a device to make and receive calls often using less than 1GB a month – often only a few MB for telemetry and location
  • Average users with daily browsing, email and search will, at best, need 3-5GB (about 100-120MB per day)
  • Power users that stream Spotify (music) and some YouTube (video) generally get by with 20-30GB per month

Best SIM Only mobile plan summary table


  • This table has last been updated March 2021
  • Summary is based on new SIM only 3/4G mobile plans with <50GB a month data use, no lock in contract
  • SIM purchases will often have an extra cost – usually from $2-15
  • The summary omits temporary sales incentives or bonus data offers (that usually are time limited)
  • All plans have unlimited national calls & text and some have optional extra cost international voice and data roaming
  • Roll-over data or data bank conditions vary. Some lose the data the end of the next month
  • VoLTE and Wi-Fi are available on some plans

Links below are to the SIM only vendor’s mobile pre-paid page. Unlike price comparison websites, GadgetGuy makes no revenue from a click-through or your purchase of a plan.

CompanyData GBRoll Over (up to)VoLTECost/mthCost/GB
Optus Flex30200GB – no 5GYes$30$1
Amaysim (owned by Optus)30/50No but includes some international outbound calls and SMSNo$30/40$1/.80
Moose Mobile (Optus)1/6/20/35No but includes some international outbound calls and SMSYes$8.80/15.80/23.80/29.80$8.80/2.63/1.19/1.00
Telstra40No but includes some international outbound calls and SMSYes$55$1.38
Woolworths pre-paid (Telstra)1/12/30/42200GB. Bonus 10% off one monthly shop to $50No$10/20/30/40$10/1.66/1/.95
ALDI (Telstra)3/20/40Continuous (conditions apply)No$15/25/35$5/1.25/.88
Boost Mobile (Telstra)5/20/30Continuous (conditions apply)Yes$20/30/40$4/1.50/1.33
Vodafone Lite10/30No – 2Mbps speed cap after data limit reachedSome areas and 5G$40/45$4/1.5
Lebara (owned by Vodafone)3/12/30NoNo$14.90/24.90/29.90$4.97/2.08/1.00

What the jargon means

  • BYOD – Bring Your Own Device means you already have a mobile phone and just looking for a plan to get the phone connected.
  • Mobile plan – Refers to a bundled mobile and plan together to be paid off as a monthly fee
  • Outright device – You buy a phone without a plan
  • Pre-Paid – You pay upfront for your mobile plan via direct debit or credit card
  • Post Paid – You are billed each month for your phones usage (this guide is not about that)
  • Unlimited standard national calls & texts – offered on most plans these days, which means for a call to fixed-line phones and mobiles, there is no limit in how many or how long you talk for.  Unlimited texts mean you can send as many texts with no further charge to any Australian mobiles.
  • International calls – This is a call to another country, and your plan may or may not include this.  If this is important to you, make sure your plan includes this or understand your charges.
  • International texts – as above but for sending a text message to a mobile in another country.
  • Data – refers to the allowance your monthly data GB.  (1 hour of low-resolution video will consume around 0.5GB of data)
  • 3G/4G/5G – refers to the connection your phone has with the mobile network.  The higher the number, the faster the data speed. The lower the number, the increased ability to pass through walls etc.  Most users will not see any real benefit of going to 5G at this time.
  • Number portability – The ability to change carrier but keep your existing number. This only works for new accounts.

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