Phone Number Spammer: How to Stop the Calls

What is a spam call, and what is spoofing?

A spam call is an unwanted call placed in bulk, usually automatically. Some are legal marketing, many are not, and a growing share are outright fraud aiming to get a payment or a security code out of you.

Spoofing is the part that makes them hard to stop. Spoofing means the caller sets the number shown on your screen to something other than their real number. Neighbour spoofing is the common variant where the displayed number shares your area code and the first few digits, so it looks local and familiar. The number you see is therefore often not the caller's number at all, and may belong to an innocent person.

Why should you not call back or press a key?

Answering, calling back or pressing the key that supposedly removes you from the list all do the same thing: they confirm that a real person is at this number. Confirmed numbers are worth more and get called more.

Calling back is worse than answering, because the number displayed may be a premium line or a line under the caller's control. Let unknown numbers go to voicemail. A genuine caller with a real reason leaves a message; automated spam almost never does.

How do you block the number on your phone?

1. Open the recent calls list and find the entry.
2. Tap the information button next to it, usually a small letter i or an arrow.
3. Scroll to the option to block the caller, then confirm.
4. For a text message, open the conversation, tap the sender's name at the top, and choose to block or to report junk.
5. Turn on your phone's built-in filter for unknown callers if you can live with the trade-off, which is that legitimate calls from people not in your contacts go quietly to voicemail.
6. Check whether your carrier offers a call-filtering service and switch it on, since it screens before the call reaches your handset.

Blocking works well against one persistent number. It works poorly against a campaign, because the next call comes from a different number.

What can you do when the number changes every time?

Blocking one at a time is a losing game against spoofing, so change level rather than repeating the same step.

• Use the carrier-level filter rather than the handset block list, because it can act on patterns instead of on single numbers.
• Turn on silencing of unknown callers, so anything not in your contacts never rings.
• Report each call rather than only blocking it, since reports are what feed the filters.
• Stop giving your number to sites that do not need it, and use a secondary number for sign-ups.
• Do not answer and stay silent to see what happens; even the connection tells the other end the line is live.

How do you report a spam call or text?

1. For a spam text, forward the message to your carrier's reporting short code, which spells the word SPAM on the keypad. Your carrier confirms the code in its own help pages.
2. Use the report junk option inside your messaging app as well, which tells the phone maker's own filter.
3. Report unwanted calls to the national regulator that handles telemarketing complaints, using its online form.
4. If money was taken, or an attempt was made, report it to the fraud agency as well, and to your bank immediately.
5. Keep a short log: date, time, the number displayed, and what the caller claimed. Reports without detail rarely go anywhere.

What is the Do Not Call list, and what does it not do?

A Do Not Call registry is a list that legitimate telemarketers are required to check and respect. Registering is worth doing and takes a couple of minutes.

What it does not do is stop criminals. A caller already breaking the law by spoofing a number is not going to consult a list. It also does not cover every category of call: political messages, charities, surveys and calls from companies you already do business with are usually treated differently. If calls continue after registering, that is expected, not a sign the registration failed.

What if your own number is the one being used by a spammer?

If strangers start calling you back angrily about calls you never made, your number is being spoofed. You cannot stop it directly, because nothing is happening on your line.

• Record a short voicemail greeting explaining that your number is being spoofed and that you did not call.
• Tell your carrier, which may be able to note it and can advise on their tools.
• Do not answer the returned calls in bulk; the wave usually passes within days or weeks as the campaign moves on.
• File a report with the regulator, which is how patterns get traced.
• Consider changing your number only if it goes on for months and is genuinely disrupting your life.

What should you never give a caller who rang you?

The safest rule is simple: nothing you would not shout across a room. Specifically, never give a password, a one-time verification code, a full card number, a bank login, remote access to your computer, or a payment in gift cards.

Anyone who calls you claiming to be your bank, a delivery company, a government agency or technical support can be verified in one move: hang up, wait a moment, and call back on the number printed on your card, your statement or your official paperwork. A genuine organisation will not object. A fraudulent one will push hard against exactly that step, and that pressure is the clearest signal you will get.