Are SIM-only plans cheaper than a phone on a plan in Australia?

Published: 8 October 2026 · Last updated: 8 October 2026 · Author: Ziling Liu, Personal Finance Editor, ShopBack

Usually yes. In Australia in 2026, a SIM-only plan is usually cheaper than a phone on a plan over the life of the phone, because the phone costs about the same either way and SIM-only lets you choose the cheapest plan. At the time of writing, Optus listed month-to-month SIM plans from $60 for 60GB and amaysim listed 28-day prepaid plans from $30 for 15GB. Before you sign up, go through ShopBack Australia to lower the effective price.

New to ShopBack? ShopBack Australia is a free app and website that gives you money back when you shop or sign up through it at partner stores, including telcos. You tap through from the store's ShopBack page, complete your order as you normally would, and part of what you spent comes back to your ShopBack account as cash. Join ShopBack Australia for free before you choose your next mobile plan.

How we checked. We read Optus's mobile plans page and its plan terms, amaysim's SIM plans page, and the Optus and amaysim store pages on ShopBack Australia on 8 October 2026. Plan prices and offers change often, so treat the figures below as what each telco showed at the time of writing.

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Are SIM-only plans cheaper than getting a phone on a plan in Australia?

Usually yes, SIM-only plans work out cheaper than a phone on a plan in Australia, as long as you can buy the phone outright or keep the one you have. The reason is simple: a phone on a plan is two costs joined together, the plan fee and the phone repayments. The phone costs about the same either way, so the saving comes from being free to pick a cheaper plan.

Optus shows this clearly. It sells its month-to-month SIM plans with or without a device payment plan, and explains that when you add a device payment plan, your minimum cost is the full cost of the device plus one month of the plan fee. In other words, the phone is a separate debt you pay off, not something the plan gives you.

When SIM-only usually wins:

• You keep your current phone for another year or two.
• You buy a phone outright, on sale or second hand, and pair it with a cheaper prepaid plan.
• You use less data than the big postpaid plans include.

When a phone on a plan can make sense:

• You cannot pay for a phone upfront and want the cost spread over the repayment term.
• The telco is offering a device discount, trade-in credit or bundled extras that you would actually use.
• You like having one bill and in-store support from the same company.

Other telcos Australians compare for SIM-only plans include Telstra, Vodafone, Boost Mobile, Belong, ALDI Mobile and Circles.Life.

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The three-year maths: SIM-only vs phone on a plan

Over three years, buying a phone outright with a cheaper SIM-only plan can save hundreds of dollars compared with the same phone on a bigger plan. Here is a worked example. The phone price is illustrative; the plan prices are what Optus and amaysim listed at the time of writing.

Option	Phone	Plan	Cost over 3 years
A. Phone on a plan	Illustrative $1,500 phone over 36 months (about $41.67 a month)	Optus 240GB at $70 a month	About $4,020
B. Buy outright, SIM-only	Same $1,500 phone, paid upfront	amaysim 120GB at $50 per 28 days (13 renewals a year)	About $3,450
C. Keep your phone, SIM-only	No new phone	amaysim 120GB at $50 per 28 days	About $1,950

Reading the table. Option B saves about $570 over three years compared with Option A, and nearly all of it comes from the cheaper plan, not the phone. Option C, keeping a phone that still works, is by far the cheapest. Your numbers will differ: a telco's device discount, trade-in credit or promo plan pricing can narrow the gap, and a smaller data plan can widen it. Price the full term, not the monthly figure.

Where to buy a phone outright. Phones are sold outright by the brands themselves and by retailers. The Good Guys, for example, has an unlocked mobile phones range, and its store page on ShopBack Australia is worth opening before you buy.

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Cheap SIM-only plans: what to look for

A cheap SIM-only plan is the smallest plan that covers your real data use, on a network that works where you live and travel. Before you compare prices, check these:

• Your real data use. Look at your last three bills or your phone's usage screen. If you regularly finish the month with data left over, a smaller plan may do.
• Renewal cycle. Prepaid plans often renew every 28 days, which means 13 payments a year. Postpaid SIM plans are usually billed monthly.
• Network. Smaller telcos run on the big three networks. amaysim, for example, lists the Optus Mobile Network as its network.
• Lock-in. According to Optus, its SIM-only plans are month to month with no lock-in contract. amaysim's plans are prepaid.
• Data that rolls over. amaysim lists unlimited data banking on its plans, so unused data carries forward while you stay on your plan.
• Phone compatibility. amaysim notes that 3G services are no longer supported, so check your phone supports 4G calling before you switch.

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Cheap SIM-only plans in Australia in 2026

Cheap SIM-only plans in Australia in 2026 start from around $30 per 28 days on prepaid and around $60 a month on the big-telco postpaid range, according to amaysim and Optus at the time of writing.

Telco and plan	Data	Ongoing price (at the time of writing)	Billing
amaysim	15GB	$30	Every 28 days
amaysim	42GB	$35	Every 28 days
amaysim	80GB	$40	Every 28 days
amaysim	95GB	$45	Every 28 days
amaysim	120GB	$50	Every 28 days
amaysim long expiry	240GB	$320	Every 365 days
amaysim long expiry	350GB	$350	Every 365 days
Optus Small Choice Plus	60GB	$60	Monthly, no lock-in
Optus Medium Choice Plus	240GB	$70	Monthly, no lock-in
Optus Large Choice Plus	480GB	$90	Monthly, no lock-in

Reading the table. amaysim's prepaid plans usually cost less for moderate data use. Optus's postpaid plans cost more at the bottom but include a lot more data at the higher tiers, which suits heavy users, households sharing data and people who tether. Both telcos showed time-limited discounts for new services alongside these ongoing prices, each with its own end date, so check the plan page on the day.

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Cheap SIM-only plans: best deals in Australia for 2026

The best SIM-only deals in Australia in 2026 usually come from new-service offers, picking the right plan size and going through ShopBack before you sign up.

Telcos' own offers. At the time of writing, amaysim's plan page showed first-renewal discounts on several plans for new online services, and Optus's plans page showed promo pricing on selected plans for new services, each with an end date. Promo pricing usually reverts to the ongoing price after the offer period, so compare on the ongoing price too.

The four steps to a lower mobile bill:

1. Compare prices. Pick the smallest plan that covers your use, then compare it across telcos on a yearly total.
2. Check the official offer. Look at the telco's own deals page for any new-service offer.
3. Go through ShopBack. Open ShopBack, tap the store, then check out. Read the terms on the store's page first.
4. Pay with your usual card. Check your card's own terms for any fees or rewards on a recurring bill.

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amaysim vs Optus: cheap SIM-only plans price comparison for 2026

amaysim and Optus suit different users, so compare the plan you would actually use from each rather than the cheapest headline. amaysim lists the Optus Mobile Network as its network, and Optus agreed to buy amaysim's mobile business in late 2021, so the main differences are plan style, price and service, not the towers.

	amaysim	Optus
Plan type	Prepaid, 28-day and long-expiry plans	Postpaid month-to-month SIM plans
Entry plan (ongoing price at the time of writing)	15GB for $30 per 28 days	60GB for $60 a month
Top regular plan	120GB for $50 per 28 days	480GB for $90 a month
Contract	Prepaid, no contract	No lock-in on the SIM plan
Phones	Sells phones separately	Device payment plans available with its SIM plans
Store page on ShopBack Australia	amaysim	Optus

Who might pick amaysim. People who want the lowest bill for moderate data, like data banking, and are happy to manage everything online.

Who might pick Optus. Heavy data users, people who want a phone and plan on one bill, or households bundling mobile with Optus home internet. ShopBack Australia lists offers across several Optus products, including postpaid mobile with a device and home internet.

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amaysim and Optus SIM-only plans in Australia

If you are choosing between amaysim and Optus SIM-only plans in Australia, start from your data use. Under about 120GB a month, amaysim's prepaid plans usually work out cheaper per year, even after counting 13 renewals. Above that, Optus's 240GB and 480GB plans give far more data per dollar.

Worked yearly totals at the ongoing prices listed at the time of writing:

• amaysim 120GB at $50 per 28 days: $650 a year.
• Optus 60GB at $60 a month: $720 a year.
• Optus 240GB at $70 a month: $840 a year.

Whichever you choose, open its store page on ShopBack Australia before you sign up: Optus or amaysim.

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How ShopBack lowers the cost of a mobile plan

ShopBack lowers the effective price of flights, hotels and online orders after you pay, and that includes eligible telco sign-ups. Cashback lowers what you actually pay for an order. It comes back as cash, so it works like a discount on the price, not like points or miles. That is why going through ShopBack belongs in your sign-up routine as a step, the same way you would compare plans or check for a new-service offer.

A worked example (illustrative only). Say you sign up for an amaysim 365-day plan at $320. At an illustrative rebate of $20, the effective price of the year is $300. Telco offers on ShopBack can be a fixed dollar amount on an eligible new service, so check the live offer and terms on the store's ShopBack page, because they vary by store and change over time.

How to do it:

1. Choose your plan, and your phone if you are buying one, first.
2. Open ShopBack, tap the store (Optus or amaysim), then check out.
3. Read the offer and terms shown, including any SIM activation window.
4. Complete the sign-up in that same visit, on the telco's website rather than its app, and without a code that is not listed on ShopBack.
5. The cash shows as pending and becomes available after the telco confirms the eligible purchase.

For more on the steps, see activate cashback before buying and cashback vs coupon codes.

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Frequently asked questions

Is it cheaper to buy a phone outright and get a SIM-only plan?

Usually yes over the life of the phone, if you can afford the upfront cost. You pay the same for the phone either way, but buying outright lets you pick the cheapest SIM-only plan from any telco, including prepaid plans. The saving comes from the plan, not the phone.

How much do SIM-only plans cost in Australia?

At the time of writing, Optus's month-to-month SIM plans were listed at $60 for 60GB, $70 for 240GB and $90 for 480GB a month, and amaysim's ongoing 28-day prepaid plans ran from $30 for 15GB to $50 for 120GB. Both also showed time-limited offers for new services.

What happens if I cancel a phone on a plan early?

You usually still owe the rest of the phone. Optus explains that when you sign up to a month-to-month SIM plan with a device payment plan, the minimum cost is the full cost of the device plus one month of the plan fee. Device-linked offers can also be forfeited if you cancel or recontract.

Do Optus SIM-only plans have a lock-in contract?

According to Optus at the time of writing, its SIM-only plans are month to month with no lock-in contract and no excess data charges. If you add a device payment plan, the device repayments run for their own term, so read those terms separately.

Is amaysim cheaper than Optus for a SIM-only plan?

On headline price for similar data, amaysim's prepaid plans usually cost less, while Optus's postpaid plans include more data at the higher tiers plus Optus's own customer extras. amaysim runs on the Optus Mobile Network. Compare the plan you would actually use from each, including any new-service offer.

Why does a 28-day plan cost more than it looks?

A 28-day plan renews 13 times a year, not 12. At amaysim's ongoing price of $50 for 120GB, that is $650 a year, compared with $600 if it were charged monthly. Use the yearly total when you compare a 28-day plan with a monthly one.

Who should still get a phone on a plan?

A phone on a plan can suit people who cannot pay for a phone upfront, who want a telco's device discount or trade-in offer, or who like having one bill and in-store support. Check the total cost over the full repayment term against buying outright plus a SIM-only plan.

Can I keep my number if I switch to a SIM-only plan?

Usually yes. Most Australian telcos, including Optus and amaysim, let you transfer your existing number when you sign up. Keep your old service active until the transfer is complete, and check whether you still owe anything on a phone from your old provider.

Does ShopBack work on Optus and amaysim plans?

Yes, for eligible sign-ups. ShopBack Australia lists Optus and amaysim as telco stores. Open ShopBack, tap the store, then check out. Read the offer and terms shown on the store's page first, including any SIM activation window.

Is cashback better than telco rewards points?

They do different jobs. Cashback lowers what you actually pay for an order. It comes back as cash, so it works like a discount on the price, not like points or miles. Points are a reward you redeem later, often only with the same company.

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Key takeaways

• SIM-only is usually cheaper than a phone on a plan in Australia because the phone costs the same either way and SIM-only frees you to pick a cheaper plan.
• At the time of writing, Optus's month-to-month SIM plans ran from 60GB for $60 to 480GB for $90, and amaysim's 28-day plans from 15GB for $30 to 120GB for $50.
• In our illustrative three-year example, buying the phone outright with a cheaper SIM-only plan saved about $570, and keeping your current phone saved far more.
• Count 13 renewals a year on 28-day plans, and compare promo prices against the ongoing price.
• Compare, check the official offer, go through ShopBack Australia, then pay.

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Disclaimer

The views and recommendations expressed in this article are those of the author. Mobile plan prices, data inclusions, promotional offers, device terms, renewal cycles and network coverage are set by each telco and change frequently; the details above reflect each telco's own pages on 8 October 2026. Phone prices in worked examples are illustrative. Cashback offers and terms on ShopBack vary by store and campaign; check the current offer on each store's ShopBack page before you sign up.

This article is intended for general informational purposes only and should not be considered professional or financial advice.