How to block spam calls and texts on your smartphone

Unwanted calls and messages can disrupt work, sleep and family time. Some are legitimate promotions, while others imitate a bank, government agency, delivery company or tradesperson. Blocking them is useful, but the aim is to reduce interruptions without cutting off appointments, emergency alerts or people you trust.

Australia’s communications regulator, the Australian Communications and Media Authority (ACMA), sets rules for telemarketing calls and marketing texts. Consent, sender identification and unsubscribe options matter, while the Do Not Call Register helps shield listed numbers from registered telemarketers. Local numbering also provides clues: mobiles commonly begin 04, and fixed-line areas use 02, 03 and 07, with +61 used internationally.

Spam prevention works best as layers. Your carrier may identify suspicious traffic, your handset can filter unknown callers and senders, and a call-blocking app can add another layer. Each layer lets some nuisance through, so using several gives better coverage than relying on one toggle.

Change settings in a controlled way, record legitimate numbers you may need later, and avoid tapping links or returning calls from unidentified senders. The built-in tools on current iPhone and Android phones are usually the safest place to begin because they do not require granting a third party access to your contacts.

Identify what is reaching you

First separate ordinary marketing from impersonation. A supermarket promotion or salon reminder is nuisance marketing; a caller claiming to be from the ATO, your bank or Australia Post may be a scam. The same distinction applies to texts promoting a sale versus one threatening a fine and demanding immediate payment.

Caller ID and sender names can be faked. A displayed number may even appear to be a Melbourne 03 line, a Brisbane mobile or a familiar organisation while actually routing through another system. Treat the apparent origin as a clue, never as proof, and be cautious with messages that create urgency or ask for payment.

Avoid calling back a suspicious number or using a link in an unexpected text. Replying STOP may stop clearly identified marketing SMS, because it confirms that the line is active, but it is ineffective against scammers and can invite further contact. For unknown callers, letting the phone ring and reviewing the message later is safer.

Use the controls already on your phone

On a recent iPhone, open Settings, then Phone, and enable Silence Unknown Callers to divert calls from numbers not in your contacts. Under Call & Text Filtering, check the carrier and spam lists if available. Silence is gentler than rejection because genuine callers can still leave a voicemail, although some numbers will still ring if you have interacted with them.

On Android, look in the Phone app for Settings, then options labelled Block unknown callers, Block spam calls or Block numbers. Labels differ across Samsung, Google and other brands, and some versions also offer a family or senior mode. In Google Messages, open Spam protection and enable it where offered, then use Report spam on messages you recognise as junk.

For unknown SMS on iPhone, use Settings > Notifications > Messages > Filter > Unknown Senders, switch the category on, then select Filter by Category. Android users can rely on Google Messages spam protection and block individual senders. Keep a small allowlist of clinics, couriers and schools whose alerts should remain easy to find.

Add network and app protections

Telstra, Optus and Vodafone may offer spam identification or call filtering through their mobile apps or customer-service teams, and these network-level signals can work before a handset rings. Check the precise features supplied for your plan, since carrier controls and handset controls are not identical.

Filtering by appearance is unreliable. International calls may arrive with a +61 display, while scammers can imitate Australian mobile numbers with an 04 prefix. Short codes used for legitimate transactional messages can also be confused with unwanted senders. Let the carrier and handset classify the traffic instead of assuming that a familiar shape means safe.

Caller-identification and call-blocking apps can help with numbers that your carrier flags poorly. Review their privacy terms, contact-upload settings and permissions, and remove access you do not need. A free trial is sensible before allowing an app to maintain a database of callers or senders.

Use Australian scam-reporting channels

The ACMA Do Not Call Register is a free Australian service for adding mobile and landline numbers. It prevents registered telemarketers from calling numbers entered in the register, although it cannot stop every promotion, spoofed call or fraudulent text. Keep the number current if you replace your handset or change service, and use a trusted family member’s consent where required.

Report suspicious messages to Scamwatch, warn others, and notify your mobile provider when a number is repeatedly abusing the network. Take a screenshot before deleting an SMS so you retain the number and wording. Avoid links asking you to “sign in”, “verify” or “refund”, and never provide a one-time passcode or PIN in response to an unexpected request.

Scammers often imitate the ATO, Services Australia, banks, police or Australia Post. Immediate danger warrants 000; non-urgent police reports in Australia can be made on 131444. A genuine agency may refer you to a verified app or official number, but it should not pressure you into moving money or revealing authentication codes to “secure” an account.

Create a simple maintenance routine

A short monthly check keeps filters useful, especially after a software update, new phone or change of carrier. Use this sequence to cover the main entry points without creating an unmanageable list:

• Enable the carrier’s current spam filter and verify that it still recognises unwanted calls.
• Turn on unknown-call silencing or blocking for both the handset and any linked smartwatch.
• Activate separate text filtering and review the blocked and filtered folders each month.
• Register eligible numbers with the ACMA Do Not Call Register and update any changes.
• Save verified contacts under clear names so important calls can pass through the filter.
• Report obvious spam, block the sender and avoid engaging with the message.
• Check account security after repeated targeting, including password and multifactor settings.

For a clean place to return to while checking general information, basic site orientation offers a minimal reference point; it does not replace official Australian guidance, carrier tools or the security controls on your phone.

Keep control without losing contact

Blocking should preserve the communications that matter. Add doctors, schools, landlords, employers and family members to trusted contacts, and confirm important organisations through a website or number you already know rather than one supplied in a message.

Because Australian mobile numbers are portable, moving between Telstra, Optus, Vodafone or another provider can keep the same number while changing the network filters around it. Re-check call and message settings after any port, and keep a current list of trusted contacts in case you replace the handset.

Also remember that the caller may be someone who has obtained a genuine phone number, so a block alone cannot establish intent. Combine technical filtering with calm verification, especially when money, passwords or identity documents are involved.

The point to remember is a layered defence: carrier screening, handset controls, official registration and careful verification work together to reduce nuisance while keeping essential contacts reachable.