What an Australian mobile number looks like and how to get one

An Australian mobile phone number has 10 digits and always starts with 04. The full format is 04XX XXX XXX, where the next two digits (the first X pair) identify which network or service provider issued the number. You get a mobile number by signing up with a carrier — either through a contract plan, a prepaid account, or a virtual network operator that runs on another company's infrastructure.

When you set up a new phone with any major carrier like Telstra, Vodafone, or Optus, or with smaller providers like Belong or iiNet Mobile, the carrier assigns you a number from their pool. If you switch providers later, you can keep your existing number by requesting a porting — a process that takes a few business days and lets you move your number to a different network without losing it.

The 04 prefix is unique to mobile phones in Australia. Landline numbers start with different digits depending on the state (02 for New South Wales and ACT, 03 for Victoria and Tasmania, 07 for Queensland, 08 for South Australia and Western Australia). This means anyone seeing a number starting with 04 knows when ready it is a mobile phone.

Key Takeaways

  • Australian mobile numbers always have 10 digits and start with 04, followed by two digits that identify the network provider.
  • You get a mobile number by signing up with a carrier through a contract, prepaid plan, or virtual network operator.
  • You can keep your number if you switch providers by requesting a port, which takes a few business days.
  • The 04 prefix distinguishes mobile numbers from landlines, which use different prefixes based on state location.
  • International callers dial your number as +61 4XX XXX XXX, dropping the leading 0 and adding Australia's country code.

How the digits break down

The structure of an Australian mobile number tells you specific information about the account. The first digit is always 4. The next two digits (positions 2 and 3) are the network identifier — they show which carrier originally issued the number. Telstra numbers often start with 041 or 042, Vodafone with 040 or 050, and Optus with 041 or 045, though these are not absolute rules and carriers can hold multiple blocks.

The remaining seven digits (positions 4 through 10) are unique to your account and are assigned sequentially as new customers sign up. This means no two people in Australia have the same mobile number, and the number stays linked to your account even if you move to a different state or change networks through porting.

When someone calls you from overseas, they dial +61 4XX XXX XXX. The +61 is Australia's country code, and the leading 0 is dropped — so a number written as 0412 345 678 becomes +61 412 345 678 for international dialling. This is standard for most countries and applies to both mobile and landline numbers.

Prepaid versus contract numbers

Both prepaid and contract mobile accounts receive a standard 10-digit number starting with 04. The difference is not in the number format but in how you pay and what services come with it. A prepaid number requires you to buy credit before you can make calls or send messages, and the credit expires if you do not use the account for a set period (usually 12 months). A contract number comes with a monthly bill and often includes a set amount of calls, messages, and data.

Virtual network operators — companies like Aldi Mobile, Kogan Mobile, or Boost Mobile that do not own their own network infrastructure — also issue standard 04 numbers. They run on the networks of the major carriers (Telstra, Vodafone, or Optus) but often charge less because they have lower overhead. Your number works exactly the same way whether it comes from a major carrier or a virtual operator.

If you let a prepaid account sit unused for the expiry period, the number is released back to the carrier and may be reassigned to someone else. Contract accounts do not expire in the same way, but if you stop paying the bill, the carrier will eventually close the account and release the number.

Porting your number to a different provider

If you want to switch to a different carrier but keep your existing number, you can request a port. The process starts with your new provider — you tell them you want to bring your current number with you, and they handle the technical work of moving it from your old carrier to their network. You will need to provide your account details from your current provider so they can verify you own the number.

The port usually takes 1 to 10 business days, depending on the carriers involved and whether there are any disputes about the account. During this time, your old provider may cut off service, or they may keep it running until the new provider takes over — this varies by carrier and plan. To avoid losing service, contact your new provider to ask what to expect and when to expect it.

Once the port is complete, your number is now on your new provider's network, and your old account is closed. You cannot port a number to a different country — if you move overseas, you will need to get a local number in that country, though you can keep your Australian number active if you want people to be able to reach you on it.

Using an Australian number if you live overseas

You can keep an Australian mobile number active even if you live outside Australia, but you need to understand how calls and messages work. If someone in Australia calls your 04 number, the call routes to you wherever you are, but you may be charged international rates depending on your overseas provider and plan. Some Australian carriers offer international roaming plans that let you use your Australian number in specific countries at set rates.

Alternatively, you can use an Australian virtual phone service — a company that holds an Australian number for you and forwards calls and messages to a phone number in your current country. This is useful if you want to maintain an Australian contact point but do not want to pay for an active mobile plan. Services like Skype, Google Voice (in limited countries), or Australian-specific providers offer this.

If you are overseas and want to receive SMS messages to an Australian number, you will need either an active Australian mobile account or a virtual service that supports SMS forwarding. Not all overseas providers support receiving Australian SMS, so check before you rely on it for important messages.

What happens if you lose or change your phone

Your mobile number is separate from your phone — the number belongs to your account with the carrier, not to the physical device. If your phone is lost, stolen, or breaks, you can get a replacement phone and use the same SIM card (the small chip that holds your account information) or request a new SIM card from your carrier. Either way, your number stays the same.

If you get a new phone that uses a different SIM card size (for example, upgrading from a micro-SIM to a nano-SIM), your carrier can issue a replacement SIM at no cost or low cost, and your number transfers to it. You do not need to notify anyone or update anything — once the new SIM is activated, calls and messages route to it automatically.

If your SIM card is damaged or lost, contact your carrier and ask for a replacement. They will verify your identity and send you a new SIM card, usually within a few business days. Until it arrives, you will not be able to make calls or send messages on that number, though people can still leave voicemail.

Frequently Asked Questions

Can I choose my own Australian mobile number?

Most carriers assign numbers automatically when you sign up. Some carriers offer premium or vanity numbers (numbers with patterns like 0412 345 345) for an extra fee, but standard numbers are assigned from available stock. If you have a specific number in mind, contact your carrier to ask whether they can reserve it.

What is the difference between 04 and other starting digits?

All Australian mobile numbers start with 04. Landline numbers start with 02, 03, 07, or 08 depending on the state. International numbers and special services use other prefixes. The 04 prefix is the only one used for mobile phones.

Do I need an Australian address to get an Australian mobile number?

Most carriers require an Australian address for billing purposes, even if you live overseas. Some virtual operators or international services may have different requirements. Contact the carrier you are interested in to confirm what they need.

What happens to my number if I do not use it for a long time?

Prepaid accounts expire if unused for 12 months (the exact period varies by carrier), and the number is released. Contract accounts do not expire the same way, but if you stop paying the bill, the carrier will eventually close the account. To keep a number active long-term, maintain at least a small balance on prepaid or keep paying your contract bill.

Can I port my Australian number if I move to another country?

You cannot port an Australian number to a foreign carrier — porting only works between Australian providers. If you move overseas, you can keep your Australian number active with an Australian carrier or virtual service, but you will need a local number in your new country for everyday use.