“Hi, I’m calling about your car accident.” You haven’t had a car accident. You don’t even own a car. Spam and scam calls are a plague — and beyond annoying, they’re dangerous: phone scams cost UK victims hundreds of millions yearly. Here’s how to stop spam calls on your mobile phone, from the built-in nuclear option to the official registers that cut them off at source.
Why you’re getting them
Your number leaks through data breaches, dodgy comparison sites, “free prize draw” entries, and plain old sequential dialling (scammers’ auto-diallers call every number in a range). Once a number is confirmed “live” (you answered once), it gets sold between scam operations and the calls multiply. The goal is usually one of: selling you something dubious (accident claims, PPI-style scams), or outright fraud (HMRC threats, bank “security” calls, tech support scams). Knowing this helps: the calls won’t stop on their own, but you can choke them off.
Step 1: register with the TPS (free, official, effective)
The Telephone Preference Service (tpsonline.org.uk) is the UK’s official opt-out register. Registering your mobile (and landline) makes unsolicited sales and marketing calls illegal — legitimate companies must check the TPS list and not call registered numbers. It’s free, takes two minutes, and takes effect within 28 days.
Important caveats: the TPS only covers legitimate UK companies. It does nothing against scammers (criminals don’t check preference registers) or overseas call centres. But it eliminates the legal nuisance calls — PPI-style, energy switching, accident claims from UK firms — which is a big chunk for most people. Also register with your mobile network’s own spam preferences while you’re at it.
Stop spam calls: use your phone’s built-in blocking
iPhone — Silence Unknown Callers. Settings > Phone > Silence Unknown Callers. Calls from numbers not in your contacts go straight to voicemail without ringing. Genuine callers leave a message; scammers don’t. This is the single most effective iPhone feature against spam — but note it also silences legitimate unknown callers (delivery drivers, GP surgeries), so check voicemail regularly. iOS also labels suspected spam (“Spam Risk”, “Scam Likely”) via your carrier.
Android — Call Screen and spam protection. Google’s Phone app (default on Pixels, available for others): Settings > Spam and Call Screen > enable “See caller and spam ID” and “Filter spam calls”. Pixels go further with Call Screen — Google Assistant answers unknown callers, asks who’s calling, and shows you a transcript before you pick up. It’s brilliant and deeply satisfying. Samsung phones have Smart Call with similar spam ID via Hiya integration (Phone app > Settings > Caller ID and spam protection).
Step 3: your network’s spam tools
UK networks offer free spam filtering — enable them:
- EE/BT: Scam Shield features, nuisance call blocking in account settings.
- O2: “Call Defence” / spam detection on newer plans.
- Vodafone: “Call Protect” options.
- Three: Scam call warnings and blocking tools in the Three app.
These work at network level — before the call reaches your phone — and they’re improving steadily. Check your network’s website or app for what’s available on your plan; most are free but not always enabled by default.
Step 4: block and report individual numbers
For persistent offenders: block the number (iPhone: tap the i > Block this Caller; Android: tap the number > Block). It won’t stop scammers (they spoof new numbers constantly — never trust that the displayed number is real), but it stops repeat pests. More usefully, report: forward spam texts to 7726 (free, works on all UK networks — the reports feed network-level blocking), and report scam calls to Action Fraud. Every report helps the networks identify patterns.
Dealing with scam calls specifically
Spam (annoying sales) and scams (criminal fraud) need different responses:
- Never engage. Don’t press 1 to “speak to an advisor”, don’t say “yes” to questions (it can be recorded), don’t call back. Just hang up. Engaging confirms your number is live and increases future calls.
- Know the red flags. Threats and urgency (“HMRC is issuing a warrant”, “your internet will be cut off today”), requests for bank details, PINs or remote access to your computer, and demands for payment in gift cards or crypto — all scams, always. Real organisations don’t operate this way.
- Verify independently. If “your bank” calls about fraud, hang up and call the number on your card. If “BT” calls about your internet, hang up and call BT’s published number. The callback rule defeats nearly every phone scam.
- Vulnerable relatives. Elderly family members are disproportionately targeted. Set up their phones with Silence Unknown Callers / spam filtering, register their numbers with the TPS, and have the conversation: no legitimate organisation demands immediate payment or personal details by phone.
The nuclear options
If spam is truly relentless: change your number (free or cheap via your network — but tell everyone important first, and update two-factor authentication everywhere), or use a second number (a cheap PAYG SIM or a virtual number) for forms, sign-ups and selling things — keeping your real number private. Data hygiene going forward: stop entering your real number in online forms, prize draws and “free” offers. Every entry is a future spam call.
The bottom line
Why blocking numbers barely works (and what does)
A quick reality check on number blocking: scammers spoof their caller ID — the number you see is fake, often mimicking your own area code to look local (“neighbour spoofing”). Blocking one fake number achieves nothing; tomorrow’s call shows a different one. That’s why the effective defences are behavioural, not number-based: Silence Unknown Callers (the call never reaches you regardless of the number shown), network-level spam filtering (which analyses call patterns, not just numbers), and the habit of never engaging. Think of it like email spam: you don’t defeat it by blocking individual addresses, you defeat it with filters. Same principle, same result — the junk still exists, it just stops reaching you.
For scam texts specifically, the phishing section of our virus-protection guide explains the red flags in detail.
To stop spam calls: register with the TPS (kills legal nuisance calls), enable Silence Unknown Callers / spam filtering (kills most of the rest), use your network’s blocking tools, report to 7726, and never engage with scammers — hang up and verify independently. You won’t reach zero — spoofed scam calls are whack-a-mole — but most people cut them by 90%+ with these steps. And the calls you do get become much easier to recognise for what they are.
