How to Stop Spam Calls and Robocalls on iPhone and Android

Originally published on CodingCush.

Your phone rings from a number that looks local. A robot voice says your bank account is locked, your National Insurance or Social Security number is suspended, or a warrant is out for your arrest. None of it is true, but the call still ruins your morning. Spam calls and robocalls are one of the most hated daily problems in the USA and the UK, and while you cannot stop every single one, you can cut them down by a lot. Here is how, step by step, on iPhone and Android.

Why You Get So Many Spam Calls

Robocalls are cheap. Software can dial thousands of numbers per hour for almost nothing, and caller ID can be faked, which is called spoofing. That is why the call appears to come from your own area code. The scammers are not choosing you personally. They dial whole number ranges, note which numbers answer, and sell lists of live numbers to other callers. Sadly, answering even once can get you more calls, because your number is now marked active.

Some calls are legal telemarketing. Many are not. The worst ones want you to panic and act fast: press 1, confirm your details, read out a code sent to your phone. A real bank, police department or tax office never works this way. If a call asks for gift cards, bank codes or remote access to your computer, it is a scam, whatever the voice says. These calls are the phone version of the tricks in our guide to spotting phishing messages, just with a voice instead of a link.

Step 1: Register Your Number for Free

Registration will not stop criminals, because criminals ignore rules. It does stop honest telemarketers, which removes a big share of the noise.

In the USA, add your number to the FTC National Do Not Call Registry. It is free, it takes two minutes, and your registration never expires. You can register mobile and home numbers, and report unwanted calls on the same website afterwards.

In the UK, register with the Telephone Preference Service, the official register run for Ofcom. It is also free. Once registered, live sales and marketing calls to your number should stop within 28 days. Companies that keep calling can be reported, and the report genuinely matters because regulators use them to fine firms.

The FTC National Do Not Call Registry homepage, where US readers can register a phone number free (Source: donotcall.gov)

Step 2: Turn On the Blocking Tools Already in Your Phone

On iPhone

1. Open Settings, then Phone.
2. Tap "Silence Unknown Callers" and switch it on. Calls from numbers not in your contacts go straight to voicemail and appear in your recent calls.
3. For a number that keeps calling, open Phone, then Recents, tap the i button next to the number, and choose "Block this Caller".

On Android

1. Open the Phone app and tap the three dot menu, then Settings.
2. Open "Caller ID and spam" and switch on "See caller and spam ID" and "Filter spam calls".
3. On Google Pixel phones, open Call Screen settings too. The assistant can answer unknown calls and show you a live transcript, so real callers get through and robots get bored.
4. To block one number, open its call in Recents, tap History, then Block and report spam.

These built in tools improve every month, because Apple and Google train them on billions of reported calls. Your reports feed the system, so reporting spam genuinely helps you and everyone else.

Step 3: Ask Your Carrier for Help

Every major carrier in the USA and the UK offers free or paid spam filtering, and most people never switch it on. In the USA, look for apps like T-Mobile Scam Shield, AT&T ActiveArmor and Verizon Call Filter. In the UK, providers such as EE, Vodafone and O2 run network level blocking and warn you about suspected scam numbers before you answer. The Ofcom guide to scam calls and messages explains what UK networks must do and how to report problem numbers, including forwarding scam texts to 7726.

Networks now also check whether a call really comes from the number it claims to use. That technology, called STIR and SHAKEN in North America, is why clearly fake calls are slowly dropping. It is not perfect yet, but combined with your phone settings it makes a real difference.

Step 4: Follow These Habits on Every Unknown Call

1. Let unknown numbers go to voicemail. Real callers leave a message. Robots rarely do.
2. Never press a number or say yes. Some scams record your voice or use keypad presses to confirm your number is active.
3. Never share a code. If a caller asks you to read back a code that just arrived by text, stop. That code unlocks your account, and sharing it hands the account to a stranger. Our guide on what two factor authentication is explains why codes must only ever be typed by you, on the real website or app.
4. Hang up and call back on the official number. If the call claims to be your bank, end it, wait a minute so the line clears, then call the number printed on your card.
5. Keep your number off public forms. Use your email instead of your phone number on prize draws, coupon sites and free trials, which are common sources of leaked numbers.

5 Robocall Scripts You Should Recognise Instantly

The voices change, but the scripts repeat. If you hear any of these, hang up:

1. The tax threat. "You owe back taxes. Pay today or officers will arrest you." Tax agencies write letters first. They never demand instant payment by phone.
2. The bank code trick. "We have sent a code to verify it is you. Please read it to me." That code resets your password or approves a payment. No real bank asks for it.
3. The computer virus call. "Your computer has sent us an error report." Microsoft and Apple do not phone customers about viruses. The caller wants remote access to your machine.
4. The prize that needs a fee. You have won a lottery you never entered, and only a small processing fee stands between you and millions. Real prizes never charge the winner.
5. The one ring callback. Your phone rings once from an unknown international number. Calling back connects you to a premium rate line that charges by the minute.

What About Blocking Apps?

Apps like Truecaller, Hiya and RoboKiller add bigger blocking databases and can help heavy targets. Read their privacy policies first, because some upload your contact list, and never pay for an app before trying the free tools above for two weeks. For most people, registration plus phone settings plus carrier filtering is enough to turn ten spam calls a day into one or two a week.

Frequently Asked Questions

Why did spam calls get worse after I answered once?

Answering proves your number is real and that a person picks up. Scammers sell confirmed active numbers, so one answered call can lead to many more. Letting unknown calls go to voicemail slowly makes your number less valuable to them.

Can I stop calls from fake local numbers?

Not completely, because the number is spoofed and changes every time. Silencing unknown callers is the strongest fix, since the spoofed number is never in your contacts. Pair it with carrier filtering, which checks call authenticity at the network level.

Is it illegal for companies to call a registered number?

In both the USA and the UK, sales calls to registered numbers are restricted, with exceptions for charities, political campaigns, surveys and companies you already do business with. Scam calls are illegal regardless of registration, which is why reporting them matters.

Should I call the number back to check who it was?

No. Some scam numbers are premium rate lines, and calling back confirms your number is active. Search the number online instead, or check whether a voicemail was left.

Final Thoughts

You will probably never reach zero spam calls, but you can absolutely reach a quiet phone. Register your number, switch on the silencing and spam filters built into your iPhone or Android, turn on your carrier's free protection, and treat every urgent unknown call as guilty until voicemail proves it innocent. Do the setup once, enjoy the silence every day.