The short answer
No single switch ends spam calls. Four free steps, done once, cut most of them. The fifth is for the people who get the worst of it.
Why the calls keep coming
A robocall costs a fraction of a cent. Calling software can dial thousands of numbers a minute, and the caller ID can be set to almost any number, often one with your own area code. So blocking the number that just called rarely helps: the next call comes from a different one.
Answering makes it worse. A live answer, a pressed key or a spoken word tells the dialer that the number belongs to a person who picks up, and that number is worth calling again.
The Do Not Call Registry: what it does and doesn’t do
The National Do Not Call Registry is a free list run by the Federal Trade Commission. Registration takes a minute and never expires.
| It stops | It does not stop |
|---|---|
| Sales calls, live or recorded, from companies that follow the law, starting about 31 days after you register | Scammers, who ignore the list. Political calls, charities, surveys, debt collectors, and companies you recently did business with |
The Registry is a list that honest telemarketers check before they dial. It does not block anything. If you are registered and still get many unwanted calls, the FTC’s own advice is that those calls are probably scams, and scams need the tools below.
Your carrier’s free blocking
The three big carriers each block likely scam calls in their network for free. These tools work before your phone rings, so they are the best first step.
| Carrier | Free tool | How to turn it on |
|---|---|---|
| T-Mobile (and Metro by T-Mobile) | Scam Shield. Scam Block stops calls labeled “Scam Likely” before they ring. | Dial #662# from the phone. #632# turns it off, #787# checks whether it is on. Also in the T-Life app. |
| AT&T | ActiveArmor. Likely fraud calls are blocked and suspected spam is labeled. | On by default for most wireless lines. Manage it in the free AT&T ActiveArmor app. |
| Verizon | Call Filter (free version). High-risk spam goes to voicemail by default. | Install the Verizon Call Filter app. On iPhone, also turn it on in Settings, Apps, Phone, Call Blocking & Identification. |
All three can catch calls you want. A pharmacy, a doctor’s office or a delivery driver calling from a busy line is sometimes labeled spam. If a call you expected never rang, check the tool’s blocked list.
Settings on your phone
Your phone has its own filters on top of the carrier’s. Two settings do most of the work.
- iPhone (iOS 26): Settings, Apps, Phone. Set Screen Unknown Callers to Ask Reason for Calling, and under Call Filtering turn on Spam. Every step is in our iPhone guide.
- Android: in the Phone by Google app, Settings, Caller ID & spam, turn on Filter spam calls. On a Samsung Galaxy, Phone, Settings, Caller ID and spam protection, then Block spam and scam calls. See our Android guide.
These settings protect the phone they are on. They do nothing for a landline, or for a parent’s phone across town.
Landlines, hidden numbers and Scam Likely
Three situations need their own answers:
- Landlines have no apps and few filters, and they are the phones many parents still answer. See stopping scam calls on a landline.
- No Caller ID calls hide the number on purpose. See how to block No Caller ID calls.
- “Scam Likely” is a label your carrier adds. It is often right and sometimes not. See what Scam Likely means.
If you do answer
- Hang up. Don’t press a key to “be removed” and don’t answer questions.
- Never call back a number from a missed call or a voicemail you don’t recognize.
- If the caller says they are your bank, the IRS, Medicare or a relative in trouble, hang up and call back on a number you already know: the one on the back of your card, on an official website, or in your own contacts.
- Never read out a code sent to your phone, and never pay with gift cards, a wire or cryptocurrency.
How to report spam calls
Reports do not stop the next call to you, but they feed the lists that block calls for everyone.
- ReportFraud.ftc.gov: scams and robocalls. For a plain robocall, choose “Just An Annoying Call”.
- donotcall.gov: a sales call that ignored the Registry.
- 7726 (SPAM): forward spam texts here, free on the major carriers.
The FTC publishes the reported numbers every business day. Carriers and call-blocking services use them, and so does PhoneShield: a number with repeated complaints is refused before it rings a PhoneShield line.
When it is a parent’s phone
Older parents get the most scam calls and lose the most to them, and every tool above has a gap for them. Filters catch known numbers, so a brand-new number gets through. Screening asks the caller for a reason and then leaves the parent to judge it, and a scammer always has a good reason ready. A landline has almost none of these tools.
PhoneShield answers the calls for them. You forward the parent’s phone, mobile or landline, to a PhoneShield number, and every call meets it first:
- Calls the network labels Scam Likely or Spam Risk, numbers on PhoneShield’s shared scam list and numbers with repeated FTC complaints are refused before the phone rings.
- Family and favorites ring straight through, even if a carrier ever mislabels them.
- Everyone else, hidden numbers included, is asked who they are and why they are calling. A real reason rings the parent; sales pitches and scams are declined; anyone else can leave a message.
It costs $29.99 a month for one line, and it reduces scam calls a great deal without promising to stop every one. Setting it up for a parent takes about ten minutes, and the plan is on the pricing page.
Questions people ask
How do I stop spam calls for free?
Turn on your carrier's free blocking (T-Mobile Scam Block, AT&T ActiveArmor or Verizon Call Filter), turn on your phone's own spam filter (on iPhone: Settings, Apps, Phone, Call Filtering, Spam; on Android: the Phone app's Caller ID and spam settings), and add your number to the National Do Not Call Registry at donotcall.gov. Together they cut most robocalls. None of them stops every scam.
Does the Do Not Call Registry stop spam calls?
It stops sales calls from companies that follow the law, about 31 days after you register. It does not stop scammers, who ignore it, and it does not cover political calls, charities, surveys, debt collectors or companies you recently did business with. Registration is free and never expires.
Why do I keep getting spam calls after blocking the numbers?
Scam call centers change numbers constantly and fake the caller ID, often with a number that looks local. Blocking one number stops that number only. Filters that look at the call itself, or a front desk that asks callers who they are, work better than a list of blocked numbers.
Should I answer a spam call and ask to be removed from their list?
No. Hang up without pressing any keys or saying anything. Answering, pressing a number or saying yes tells the dialer the line is live, and that usually brings more calls. Real companies honor a Do Not Call request; scammers do not.
How do I report spam calls?
Report scam and robocalls at ReportFraud.ftc.gov (for a plain robocall, choose "Just An Annoying Call"). Report telemarketing calls that ignore the Do Not Call Registry at donotcall.gov. Forward spam texts to 7726 (SPAM). The FTC publishes the reported numbers every business day, and call-blocking tools, PhoneShield included, use that data.
What is the best way to stop scam calls to an elderly parent?
Settings on the parent's phone help, but they still leave the parent to judge each caller, and landlines have few tools at all. A screening service that answers for them works better: PhoneShield refuses known scam numbers before the phone rings, lets family through, and asks everyone else who they are and why they are calling.