To stop harassing phone calls, work in layers: block the number on your phone and turn on your carrier’s free spam filter, add your number to the National Do Not Call Registry, keep a written log of every unwanted call, and report the calls to the federal agency that handles that caller type. If the calls continue, a written cease and desist letter can stop a debt collector, and federal law lets you sue for $500 to $1,500 per illegal robocall.
Block the Number and Turn On Carrier Filtering
When you answer an unwanted call, say clearly that you want the caller to stop calling and to remove your number from their list, then hang up. Don’t confirm your name, address, or any financial detail. That single verbal request creates a legal obligation for legitimate companies to take you off their internal call list.
After the call, block the number in your phone’s call history. Every modern smartphone lets you do this in a few taps. It won’t stop operations that rotate through spoofed numbers, but it cuts down on repeat contacts from less sophisticated callers.
Your carrier offers a stronger filter for free. AT&T has ActiveArmor, T-Mobile has ScamShield, and Verizon has Call Filter. Each screens incoming calls against databases of known spam numbers and can send suspected robocalls straight to voicemail or block them outright. Download your carrier’s app from your phone’s app store; the basic tier costs nothing.1Federal Communications Commission. Call Blocking Tools and Resources
If you previously agreed to get automated calls or texts from a company, you can pull that consent back at any time by any reasonable method: telling them verbally, replying “STOP” to a text, emailing, or using a form on their website. Once you revoke, the company must stop within 10 business days.2Federal Communications Commission. FCC DA 25-312 Order
Sign Up for the National Do Not Call Registry
The National Do Not Call Registry is a free FTC service that tells legitimate telemarketers you don’t want sales calls. Register your home or cell number at DoNotCall.gov, or call 1-888-382-1222 from the phone you want to register. Online registrations require you to click a confirmation link in the email you receive within 72 hours.3Federal Trade Commission. National Do Not Call Registry FAQs
Your number appears on the registry the next day, but telemarketers get up to 31 days to stop calling. After that, a sales call from a company you haven’t done business with is a reportable violation.4Federal Trade Commission. National Do Not Call Registry
The registry has real gaps. Political organizations, charities, survey companies, and debt collectors can still call. Companies you’ve done business with can keep calling for up to 18 months after your last purchase, delivery, or payment, and for up to three months after an inquiry or application. Even these callers must stop if you ask them to, so write down the date of that request.5Federal Trade Commission. Q and A for Telemarketers and Sellers About DNC Provisions in TSR
Scammers who are already breaking the law will not check the registry. Treat it as one layer alongside carrier blocking and complaint filing, not a fix on its own.3Federal Trade Commission. National Do Not Call Registry FAQs
One more rule worth knowing while you’re documenting: under the Telemarketing Sales Rule, telemarketers cannot call your home before 8 a.m. or after 9 p.m. in your local time zone without your prior permission. A call at 7:30 a.m. or 9:15 p.m. is a violation worth recording.6Federal Trade Commission. Complying with the Telemarketing Sales Rule
Keep a Call Log
A detailed call log is the foundation for everything that comes next. Agency complaints, cease and desist letters, and lawsuits all depend on your records. Without documentation, you have frustrating memories; with it, you have evidence of a pattern.
For every unwanted call, write down:
- The date and exact time of the call.
- The number that appeared on caller ID, even if you suspect it’s spoofed.
- The name of the person and the company they claimed to represent, if given.
- A brief factual summary of what was said, including threats, abusive language, or requests for payment.
- Whether it was a live person, a prerecorded robocall, or an automated voice prompt.
Recording Calls
An audio recording is stronger evidence than a written note. Federal law lets you record a phone call as long as at least one party consents, and your own consent counts.7Office of the Law Revision Counsel. 18 U.S. Code 2511 – Interception and Disclosure of Wire, Oral, or Electronic Communications
Roughly a dozen states require all parties to consent before a call can be recorded. If you live in one of those states, or the caller is located there, recording silently could expose you to liability. Check your state’s wiretapping law first, or just tell the caller the conversation is being recorded. Many harassing callers hang up the moment they hear that, which solves the problem on its own.
Report the Calls to the Right Agency
Your complaint may not fix your individual problem overnight, but it feeds the databases that trigger investigations and enforcement actions. Where you file depends on who is calling.
Telemarketing, Robocalls, and Scams
For unwanted sales calls, robocalls, and scam calls, report to the Federal Trade Commission at ReportFraud.ftc.gov. If you’re already on the Do Not Call Registry and it’s been more than 31 days, you can also file through DoNotCall.gov. Include the details from your call log.8USAGov. Telemarketer and Scam Call Complaints
Caller ID Spoofing
When callers disguise their identity with a fake number on your caller ID, that’s the FCC’s territory. Under the Truth in Caller ID Act, transmitting misleading caller ID information with intent to defraud or cause harm is illegal. File at consumercomplaints.fcc.gov.9Federal Communications Commission. Caller ID Spoofing
Debt Collector Harassment
If the calls come from a debt collector using abusive tactics, file with the Consumer Financial Protection Bureau at consumerfinance.gov/complaint. The CFPB enforces the Fair Debt Collection Practices Act, which prohibits harassment, threats, and deception in collection. The CFPB forwards the complaint to the company, which generally has 15 days to respond.10Consumer Financial Protection Bureau. Know Your Rights When a Debt Collector Calls
Send a Cease and Desist Letter to a Debt Collector
A written cease and desist letter is the strongest tool available against debt collector calls specifically. Under the FDCPA, once a collector receives your written request to stop communicating, they must comply.11Office of the Law Revision Counsel. 15 U.S. Code 1692c – Communication in Connection with Debt Collection
The request must be in writing. A phone call asking them to stop doesn’t trigger the FDCPA’s cease-communication rule. Your letter should include your full name and mailing address, the date, the name and address of the collection agency, and a clear statement demanding they stop all communication with you about the debt. Reference 15 U.S.C. ยง 1692c(c).
Send it certified mail with return receipt requested. The return receipt is your proof they received the demand. After that, the collector can only contact you for three narrow reasons: to confirm they’re stopping collection efforts, to notify you they may pursue a specific legal remedy, or to tell you they intend to sue.11Office of the Law Revision Counsel. 15 U.S. Code 1692c – Communication in Connection with Debt Collection
The letter stops the phone calls, not the debt. The collector can still report the debt to credit bureaus and can still sue to collect. If you owe the money, silencing the calls doesn’t make the obligation disappear; it just gives you control over how you communicate about it.
Sue for Damages
When documenting and reporting aren’t enough, both the TCPA and the FDCPA give you the right to sue the caller directly. This is where your call log pays off.
TCPA Lawsuits for Robocalls
The Telephone Consumer Protection Act lets you sue in state court for $500 per illegal robocall or autodialed call. If the court finds the violation was willful or knowing, it can triple the amount to $1,500 per call.12Office of the Law Revision Counsel. 47 USC 227 – Restrictions on Use of Telephone Equipment
The math adds up fast. Thirty illegal robocalls at $1,500 each is $45,000. That’s why some attorneys handle TCPA cases on contingency. You can also use small claims court for smaller violations, though a corporate defendant may move the case to a higher court where they can bring formal representation and discovery.
FDCPA Lawsuits for Debt Collectors
For debt collector violations, the FDCPA lets you recover any actual damages plus up to $1,000 in additional statutory damages per lawsuit. If you win, the court can also award attorney’s fees and court costs, which means a lawyer may take your case without an upfront payment.13Office of the Law Revision Counsel. 15 U.S. Code 1692k – Civil Liability
The $1,000 cap is per case, not per call, so FDCPA claims are smaller in dollar terms than TCPA claims. The attorney’s fees provision is the real lever. Lawyers have a financial reason to pursue even modest FDCPA cases, and debt collectors know defending a lawsuit costs far more than $1,000 regardless of outcome.
Many states also have their own consumer protection and telemarketing laws with additional statutory damages, sometimes $500 to $10,000 per violation. State claims can stack on top of federal ones, so check whether your state gives you a private right of action.
When Calls Become Criminal
Most unwanted calls are civil matters. Some cross into criminal conduct. Federal law makes it a crime to use a phone to threaten, abuse, or harass someone in interstate communications, punishable by up to two years in prison. That includes anonymous calls made with intent to harass, making a phone ring repeatedly to harass the person at that number, and making repeated calls solely to harass a specific person.14Office of the Law Revision Counsel. 47 U.S. Code 223 – Obscene or Harassing Telephone Calls in the District of Columbia or in Interstate or Foreign Communications
If a caller makes direct threats of violence or you feel you’re in physical danger, call 911. For menacing calls that don’t rise to that level, file a report with your local police. State harassment and stalking laws often have lower thresholds than federal law and can be easier for local prosecutors to act on. Save your call log and any voicemails; they become evidence in a criminal investigation.