How to Hide Your Number When Calling in Australia – No Caller ID
How to hide your number when making a call in Australia involves dialling a short code before the number (1831, or #31# from a mobile), turning off “Show My Caller ID” on your phone, or asking your telco to block your caller ID on all calls. A separate silent number service keeps your number out of directories. These options are available from Telstra, Optus, Vodafone and other providers.
Most Australians need caller ID blocking for privacy protection, avoiding unwanted callbacks, or maintaining anonymity during sensitive communications. Blocking your number for a single call is normally free. Fees for other privacy services vary by provider, so check with yours.
Understanding the difference between per-call blocking, permanent caller ID blocking and silent numbers helps you choose the right privacy solution. Additionally, certain limitations apply: calls to Triple Zero (000) always show your number, and law enforcement can obtain call records through legal processes.
TL;DR
- Dial 1831 (or #31# from a mobile) before the number to hide your number for one call. The old US-style *67 code is not the Australian standard
- Contact your telco to block your caller ID permanently, or turn off “Show My Caller ID” in your phone settings. Ask about fees, which vary by provider
- Emergency services (000) always see your number, and law enforcement can obtain records through legal channels despite blocking
- Smartphone settings offer built-in caller ID blocking options for both Android and iPhone users
Understanding Caller ID Blocking in Australia
Caller ID blocking conceals your phone number from the recipient’s display when you make outgoing calls. This privacy feature works by instructing your telecommunications carrier to suppress the transmission of your number identification data to the receiving party’s network.
Australian telecommunications networks support caller ID blocking through two primary methods: dialling a code for a single call and asking your telco to block caller ID on all calls. Furthermore, modern smartphones have a “Show My Caller ID” setting that hides your number on all outgoing calls.
Temporary vs Permanent Number Hiding
Per-call caller ID blocking conceals your number for individual calls by dialling 1831 or, from a mobile, #31#, before the number. This method works immediately without any carrier setup. However, you must remember to dial the code before each call.
Conversely, permanent caller ID blocking automatically hides your number on all outgoing calls. You can turn off “Show My Caller ID” on your phone, or ask your telco to block caller ID on all calls from your service. Fees vary by provider, so check with yours.
| Method | Cost | Setup Required | Usage |
|---|---|---|---|
| Per-call code (1831 or #31#) | Normally free | None | Per-call basis |
| Permanent blocking via telco | Check with your telco | Contact your telco | All calls automatically |
| Phone settings (Show My Caller ID) | Free | Device settings | All calls from that phone |
Legal Framework and Regulations
The Australian Communications and Media Authority (ACMA) regulates telecommunications services in Australia and publishes guidance on making your phone number more private. Australian law permits individuals to block their caller identification for legitimate privacy purposes, including personal safety.
However, significant limitations apply to caller ID blocking in Australia. Your number will always show when you call Triple Zero (000), even if it is blocked or silent, so operators can confirm your location and call you back. Similarly, law enforcement can obtain call records through legal processes.
Moreover, some businesses and organizations reject calls from blocked numbers as a security measure. Banking institutions, healthcare providers, and government departments often require caller identification for verification purposes, making permanent blocking potentially inconvenient for essential services.
When Caller ID Blocking Proves Useful
Privacy protection represents the primary reason Australians use caller ID blocking. Individuals selling items online, contacting strangers through classified advertisements, or making sensitive inquiries benefit from number concealment to avoid unwanted callbacks or harassment.
Business professionals frequently employ caller ID blocking when conducting market research, competitive analysis, or confidential negotiations. Additionally, healthcare workers, legal professionals, and social workers use number blocking to maintain professional boundaries while contacting clients from personal devices.
Personal safety situations also warrant caller ID blocking, particularly for individuals experiencing domestic violence, stalking, or harassment. Furthermore, parents teaching teenagers about phone etiquette often use blocking features to demonstrate responsible communication practices without revealing family contact information.
Many Australians use caller ID blocking for privacy, safety or confidentiality.
What is a Silent Number in Australia
A silent number is a service that keeps your number out of public phone directories and directory assistance services. According to the ACMA, a silent number is also automatically barred from showing on the phone you call, except when you call Triple Zero (000).
Silent numbers are arranged with your telco, ideally when you sign up. They keep your number out of phone directories and directory assistance services. Some telcos charge an ongoing fee, so compare providers before choosing.
Silent Numbers vs Caller ID Blocking
Silent numbers and caller ID blocking overlap but are not the same. A silent number keeps you out of directories and is barred from showing on the phone you call, while caller ID blocking hides your number from the called party for one call or all calls but does not remove directory listings.
| Feature | Silent Number | Caller ID Blocking |
|---|---|---|
| Directory Listing | Suppressed | Not affected |
| Call Display | Barred from showing to the person you call | Hidden, usually shown as private or withheld |
| Emergency Services (000) | Number always shows | Number always shows |
| Business Acceptance | Shown as hidden, so some may not answer | Some businesses and people will not answer |
Be aware that, like blocked calls, calls from a silent number may go unanswered by people and businesses that screen calls from hidden numbers.
Directory Suppression vs Call Anonymity
Directory suppression through silent numbers prevents public access to your number through directories and directory assistance services. Check with your telco about how and when your details are removed.
Conversely, call anonymity through caller ID blocking hides your number from the person you call but does not remove your directory listing.
Silent numbers also help keep your number from being found through directories.
Cost and Availability Through Australian Telcos
Fees for silent numbers vary by provider. Telstra stopped charging for Silent Lines from 18 February 2018, and Optus has also not charged for silent lines for many years, according to ACCAN. Check Vodafone, TPG, iiNet and other providers for their current fees.
Previously published information may persist in cached online directories or printed materials for some time after activation.
- Telstra: no fee for Silent Line since 18 February 2018
- Optus: no fee for silent lines, per ACCAN (check with Optus)
- Vodafone: check with Vodafone for current fees
- TPG and iiNet: check with your provider for current fees
Business customers should ask their provider about options for business listings.
Your telco may need to verify your identity. Moreover, silent numbers remain in place until you ask your telco to remove them, unlike per-call blocking, which you must dial each time.
How to Hide Your Number Temporarily (Per Call)
Per-call number hiding allows callers to conceal their number for individual calls without changing their service. This provides flexibility for privacy-conscious users who need selective anonymity while keeping caller ID visible for most calls.
Using 1831 or #31# for Mobile and Landline Calls
The ACMA says to block caller ID for an individual call you dial 1831 (or #31# from a mobile) and then the number you are calling. Telstra also gives #31# for mobiles. Dial the code immediately before the number, and the code applies to that call only.
For example, from a mobile, dialling #31# 02 9876 5432 connects the call and your number should not show on the recipient’s phone, which will normally show a withheld or private number message. The next call returns to your normal setting.
Codes for Mobile and Landline Services
The code you use depends mainly on whether you are calling from a mobile or a landline-style service, rather than which carrier you are with. If one code does not work on your service, check with your telco.
| Carrier | Mobile | Landline or home phone | Note |
|---|---|---|---|
| Telstra | #31# | 1831 | Telstra also lists *31# to show your number again on a call |
| Optus | #31# | 1831 | Check with Optus if the code does not work |
| Vodafone | #31# | 1831 | Check with Vodafone if the code does not work |
| TPG/iiNet | #31# | 1831 | Check with your provider if the code does not work |
The #31# code is a standard GSM code for mobiles, and 1831 is the standard code for landline-style services. Results can vary depending on the networks involved, so test before you rely on it.
Step-by-Step Instructions for Smartphones
Smartphone users can hide their number for one call by dialling a code, or for all calls using a phone setting. The steps are similar on Android and iOS.
- Open the phone dialer application on your smartphone
- Enter #31# followed immediately by the complete phone number
- Check the code is entered correctly before the number
- Press the call button to initiate the blocked connection
- Verify the call connects with suppressed caller identification
Android users can also access caller ID settings through the Phone app’s settings, but the menu names vary by phone model and Android version. Similarly, iPhone users navigate to Settings > Phone > Show My Caller ID to toggle identification display, though this affects all outgoing calls rather than individual calls.
Dialling the code manually is a simple method that works on most services.
Verification Methods to Confirm Number is Hidden
Verifying successful caller ID suppression requires testing the blocking mechanism before important calls. Consequently, users should employ multiple verification methods to ensure their number remains concealed during sensitive communications.
The most effective verification involves calling a trusted contact who can confirm what appears on their phone, such as a withheld number, private number or unknown caller message. Telstra also lets mobile customers check their setting by dialling *#31#.
- Call a friend or family member using the #31# or 1831 code
- Ask them to describe what appears on their caller ID screen
- Test different phone numbers to ensure consistent blocking
- Verify the method works across landline and mobile recipients
- Document successful blocking codes for future reference
Furthermore, you can test your setting by calling a number you control, such as a second phone.
Test your number-hiding setting with a trusted contact before relying on it.
How to Hide Your Number Permanently
Permanent caller ID blocking eliminates the need to dial a code before each call. Therefore, users seeking consistent privacy can use their phone settings or ask their telco to block caller ID on all calls.
Contacting Your Service Provider for Permanent Blocking
The ACMA says that to block caller ID on all calls from your phone you should contact your telco. Moreover, this carrier-level blocking applies across all outgoing calls without needing action each time.
Contact your telco’s customer service to request permanent caller ID blocking. Alternatively, you can turn off “Show My Caller ID” in your phone settings.
- Call customer service and request “permanent caller ID blocking”
- Provide account verification details for security confirmation
- Ask how long it takes to take effect
- Test the service by calling different numbers
- Confirm blocking works on both mobile and landline recipients
Fees and conditions for permanent blocking vary by provider, so ask your telco before you proceed.
Smartphone Settings for Automatic Caller ID Suppression
Modern smartphones provide built-in settings for automatic caller ID blocking without carrier involvement. Consequently, users can configure device-level suppression that works independently of network provider restrictions.
iPhone users access caller ID settings through Settings > Phone > Show My Caller ID. Turning this toggle off hides your number on outgoing calls.
Android devices offer caller ID settings in the Phone app’s settings, but the menu location and wording vary by manufacturer and Android version. Check your phone’s manual or settings search.
| Device Type | Setting Location | Option Name |
|---|---|---|
| iPhone | Settings > Phone | Show My Caller ID (turn off) |
| Android phones | Phone app > Settings (menu names vary by model) | Caller ID or Show My Number (turn off) |
Carrier-Specific Instructions for Australian Networks
Telstra customers on a mobile can dial #31# before a number to hide it for one call, or turn off the “Show My Caller ID” setting on their phone. Check postpaid mobile plans and Telstra support for other options.
Optus subscribers can use the same dial codes, or contact Optus to ask about blocking caller ID on all calls. Check Optus support for contact details.
Vodafone users can use the same dial codes, or contact Vodafone to ask about blocking caller ID on all calls. Check Vodafone support for contact details.
Ask your telco how long permanent changes take, and test them afterwards.
Managing Permanent Settings and Exceptions
Permanent caller ID blocking requires careful management to ensure appropriate number visibility when you need it. Therefore, understand how to show your number for individual calls.
Emergency services automatically receive your number when you call Triple Zero (000), whatever your blocking settings. Law enforcement can also obtain call records through legal channels.
Telstra says mobile customers whose number is hidden can show it for one call by dialling *31# before the number. Other providers may use different methods, so check with your telco.
- Dial *31# followed by the complete phone number (Telstra mobile)
- Your caller ID will display normally for this call only
- Subsequent calls return to automatic blocking mode
- Use this method for business calls or service appointments
- Document important numbers that require caller ID visibility
Some providers may offer other call display options, so ask your telco what is available.
Carrier-Specific Methods for Australian Networks
The basic dial codes are the same across providers, but support options and fees can differ. Check each provider’s website for current details.
Telstra Caller ID Blocking Procedures and Costs
Telstra mobile customers can hide their number for one call with #31# or by turning off “Show My Caller ID” in phone settings. Telstra stopped charging for Silent Lines from 18 February 2018. Use the My Telstra app or Telstra support to ask about other options.
Ask Telstra how long any change takes to apply and whether business plans have different options.
Check with Telstra for any other call display features that apply to your service.
Optus Privacy Settings and Silent Number Options
Optus customers can use the standard dial codes to hide their number for one call. According to ACCAN, Optus has not charged for silent lines for many years. Check Optus for current options and fees.
Use the My Optus app or Optus customer support to ask about other privacy options and how long changes take.
Prepaid and postpaid customers can both use the dial codes at no extra charge.
Vodafone Caller Identification Suppression
Vodafone Australia customers can use the standard dial codes to hide their number for one call. Check Vodafone for current options, fees and how to request permanent blocking.
Use the My Vodafone app or Vodafone customer support to ask how long changes take, and mention it if you have safety concerns.
Vodafone may offer features for blocking unwanted incoming calls, so ask about those separately from hiding your own number.
Smaller Carriers and MVNO Options
Mobile Virtual Network Operators (MVNOs) like Boost Mobile, Amaysim, and Woolworths Mobile run on a host network, and the standard dial codes should generally work. Check each provider’s support pages for fees and options.
Belong and other smaller providers may handle permanent blocking and silent numbers differently, so check with your provider before relying on a specific feature.
Smaller providers may handle requests differently and may take longer, so ask them directly.
Some budget providers handle changes only through support, so check what is possible before you sign up.
Mobile vs Landline Caller ID Blocking
Mobile phones and landline systems use slightly different codes. Consequently, understanding these distinctions helps you choose the most effective method.
Smartphone Privacy Settings and Built-in Options
Modern smartphones include a caller ID setting in their operating systems. iPhone users access this feature through Settings > Phone > Show My Caller ID, while Android menus vary by manufacturer.
These settings can be turned on and off at any time, but they apply to all outgoing calls. To hide your number for one call only, dial #31# before the number.
Be careful with third-party apps that claim to hide your number, as they may collect your data. Check the app’s privacy policy.
Traditional Landline Blocking Through Service Providers
For a landline-style service, dial 1831 before the number to hide it for one call. To block caller ID on all calls, contact your provider, because fees and processes vary by provider.
If a code does not work on your service, check with your provider, as results can depend on the network.
Business phone systems may have their own caller ID settings, so ask your provider or IT support.
Effectiveness Comparison and Limitations
| Feature | Mobile Phones | Landline Systems |
|---|---|---|
| Per-call code | #31# | 1831 |
| Permanent blocking | Phone setting or ask your telco | Ask your telco |
| Cost | Per-call codes normally free | Check with your provider |
Results can vary between networks, particularly where calls pass through several providers, so test your setting before relying on it.
Emergency services can see your number on both mobile and landline calls, so 000 calls always show your number. Similarly, law enforcement can obtain call records through legal processes.
International calling presents challenges for caller ID blocking, as foreign networks may handle privacy settings differently. Therefore, users making overseas calls should not assume their number will stay hidden.
Limitations and Exceptions
While caller ID blocking provides useful privacy protection in many situations, several limitations affect its reliability. Understanding these exceptions helps users decide when blocking works and when alternative privacy measures become necessary.
Emergency Services Can Always See Your Number
Emergency services override all caller ID blocking and silent number settings. When you call 000, your number will always show, so the operator can confirm where you are, contact the nearest emergency service, and call you back if the line drops.
Consequently, fire, police, and ambulance services receive your number even when you use blocking or a silent number.
Some Businesses and Government Agencies Bypass Blocking
Law enforcement and other authorised agencies can obtain call records through legal processes, which bypass standard privacy protections.
Additionally, some businesses use systems that capture caller data in ways that may not respect caller ID blocking, particularly for toll-free and premium call services. Insurance companies and banks may still be able to identify you in other ways, such as when you quote account details.
Your own telco keeps records of the calls you make, including blocked ones, so complete anonymity is not possible.
International Calling Considerations
International networks may handle Australian caller ID blocking differently. When making overseas calls, your number may display on recipient devices despite local blocking.
Different countries implement varying caller identification standards, creating gaps in privacy protection. Test before relying on it for sensitive calls.
Furthermore, internet calling apps like WhatsApp and Skype use their own systems and display your account details or number according to their own settings, not your telco’s settings.
When Caller ID Blocking May Not Work Effectively
Several technical scenarios can reduce blocking effectiveness. Network differences between providers can sometimes cause a number to be shown despite blocking.
Older phone systems may handle blocking codes differently, so test your setting.
Call forwarding and conference calling can also affect whether your number is hidden. When calls route through multiple systems or third-party services, caller details may be shown differently.
Finally, phone updates and settings changes can reset your caller ID setting. Test your privacy settings from time to time by calling a trusted contact.
Costs and Service Fees
Hiding your number for one call by dialling #31# or 1831 is normally free. However, this requires manual action for every call, which can become inconvenient for frequent users.
Fees for permanent caller ID blocking vary by provider and some providers may not charge, so ask your telco. Telstra stopped charging for Silent Lines from 18 February 2018, and Optus has also not charged for silent lines for many years, according to ACCAN.
Silent Number Service Pricing
Silent numbers keep your number out of directories and are barred from showing on the phone you call (except for 000 calls), according to the ACMA. Some telcos charge an ongoing fee, so compare providers before choosing.
Check the current fees with each provider, including Vodafone, TPG and iiNet, as they can change.
| Carrier | Per-call code | Permanent blocking | Silent number |
|---|---|---|---|
| Telstra | Free | Ask Telstra | No fee since 18 Feb 2018 |
| Optus | Free | Ask Optus | No fee per ACCAN (check Optus) |
| Vodafone | Free | Ask Vodafone | Check with Vodafone |
Cost-Benefit Analysis
The value of each option varies with your usage patterns and privacy requirements. Occasional callers often find the free per-call code sufficient.
Business users and frequent callers may prefer permanent blocking. The convenience factor eliminates the need to remember dialling codes, while consistent privacy protection reduces the risk of identification during important calls.
For users concerned about harassment or requiring maximum anonymity, a silent number combined with caller ID blocking can help. If you feel unsafe, contact the police, and see the ACMA and your telco for advice on managing unwanted calls.
Additionally, users switching between prepaid vs postpaid mobile plans should check how the plan handles privacy features, as fees and options differ between providers.
Privacy Considerations and Best Practices
Understanding when to hide your number requires careful consideration of both privacy needs and communication effectiveness. Appropriate scenarios include calling unknown businesses, responding to classified advertisements, or contacting service providers where personal information security matters most. However, blocking caller ID can reduce the chance your call is answered.
When Caller ID Blocking Is Appropriate
Professional situations often warrant number blocking to maintain privacy boundaries. Real estate inquiries, job applications through third-party platforms, and initial business consultations represent ideal use cases. Additionally, personal safety concerns justify caller ID blocking when contacting unfamiliar parties or responding to online marketplace listings.
Medical appointments, legal consultations, and financial service inquiries also benefit from anonymous calling practices. These sensitive communications protect personal information while maintaining professional interaction standards. Furthermore, temporary blocking proves valuable when conducting research calls or gathering information from multiple service providers.
Potential Negative Impacts on Recipients
Calls from hidden numbers are less likely to be answered. Recipients increasingly associate private numbers with spam, telemarketing, or scam activity, creating immediate trust barriers. Consequently, important calls may go unanswered.
Emergency situations become particularly problematic when caller identification remains hidden. Healthcare providers, emergency services, and family members may not answer blocked calls during critical moments. Moreover, business relationships suffer when professional communications appear anonymous, potentially damaging credibility and response rates.
Call screening technology and phone settings can automatically silence or filter private numbers, meaning your hidden caller ID may never reach human recipients. Many people and businesses do not answer unknown calls, particularly in sectors like finance and healthcare.
Alternative Privacy Protection Methods
Secondary phone numbers provide effective privacy protection without the drawbacks of completely blocked calls. Virtual number and second-number apps allow you to keep separate contact numbers for different purposes. These solutions preserve caller identification while protecting your primary number.
Temporary mobile services offer another viable alternative for privacy-conscious users. A separate prepaid SIM can keep your main number private without long-term commitments, although you still need to verify your identity to activate it. Additionally, disposable number services provide short-term solutions for specific transactions or inquiries.
Communication apps represent modern alternatives to traditional phone privacy methods. WhatsApp, Telegram, and Signal enable encrypted messaging and calling without revealing personal phone numbers. These platforms also support temporary account creation, providing enhanced anonymity for sensitive communications.
Balancing Privacy with Communication Effectiveness
Effective privacy management requires strategic decision-making about when to reveal or conceal caller information. Consider using temporary blocking for initial contact attempts, then revealing your number for follow-up conversations once trust establishes. This approach maximizes both privacy protection and communication success rates.
Professional communications benefit from transparent caller identification, while personal inquiries may warrant anonymous calling approaches. Develop consistent protocols for different communication types, ensuring your privacy practices align with relationship-building goals. Remember that excessive privacy measures can hinder legitimate business and personal connections.
Technology solutions increasingly offer more control than blanket caller ID blocking. For example, you can hide your number for a single call with a dial code while leaving your number visible for other calls. This approach balances privacy with communication effectiveness.
Strategic privacy management involves revealing caller ID when building trust matters most, while maintaining anonymity for initial inquiries and sensitive communications.
Frequently Asked Questions
Does *67 work on all Australian mobile networks?
No. *67 is a US code and is not the Australian standard. In Australia, dial 1831 (or #31# from a mobile) before the number. If a code does not work on your service, contact your telco.
How much does permanent caller ID blocking cost in Australia?
It depends on the provider, and some providers do not charge. To block caller ID on all calls, the ACMA says to contact your telco, so ask about fees. Telstra stopped charging for Silent Lines from 18 February 2018, and Optus has also not charged for silent lines for many years, according to ACCAN. Contact your provider for exact pricing.
Can emergency services still see my number if I block caller ID?
Yes, your number always shows when you call Triple Zero (000), even if it is blocked or silent. This lets the operator confirm where you are, contact the nearest emergency service, and call you back if the line drops.
How do I block my number using iPhone or Android settings?
On iPhone: Go to Settings > Phone > Show My Caller ID and toggle it off. On Android: Open the Phone app and look for a caller ID or “Show my number” option in the Phone app’s settings, because the menu names vary by manufacturer. These settings will hide your number on all outgoing calls until you change them back.
Will banks and government agencies accept calls from blocked numbers?
Some banks and government agencies may not accept calls from hidden numbers, and some may not answer them. You may need to show your number when calling these organisations, for example by dialling *31# on a Telstra mobile or turning off the setting.
Is there a difference between *67 and #31# for blocking calls?
#31# is the code for mobiles and 1831 is the code for landline-style services. *67 is a US code, not the Australian standard.
Can I block my number for some contacts but not others?
Yes, per call. Dial #31# (mobile) or 1831 (landline) before the number to hide your number for that call only, and leave your caller ID on for other calls.
Are there any legal restrictions on caller ID blocking in Australia?
Hiding your caller ID is legal in Australia for legitimate privacy purposes. However, using hidden numbers for harassment, fraud, or other illegal activities is prohibited. Law enforcement can obtain call records through legal processes.
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