According to Lifehacks #1777, pressing "9" on a phone will apparently add your number to an internal do not call list on the other end. This is also apparently verified by a very hoaky looking website. But I cannot find a solid confirmation or denial of this Lifehack.


Is it true that I can press "9" on a phone to put a telemarketer on a do not call list?

  • 1
    A real lifehack would be 1. Move away from your home area code. 2 Get a call blocker app. 3. Block all numbers from your home area code except those on contact list. -- Blocks 99% of all telemarketer calls for me. ¯_(ツ)_/¯ Commented Sep 20, 2019 at 0:55

4 Answers 4


Short answer: no.

Pressing "9" by itself while in dial-pad simply stores a 9 to be dialed along with whatever other numbers are entered afterward when you press "Send".

Of course, this and the sketchy website call into question everything else advised by "Lifehacks #1777" -- and more generally in any unsupported or anonymous advice source.

If you do this while connected on a call, the number isn't even stored for later dailing -- it's just sent as an immediate tone, as if you were using a tone-controlled system (entering your account number on your bank's service line, for instance). This is uncomfortable for someone on the other end who might be wearing a headset, but won't put you on a "do not call" list -- and, depending how bad a day the caller has already had, might get you entered as a "good prospect" to receive ten times as many "spam" calls.

If you get a call you won't want to listen to (robocall, telemarketing, etc.) just hang up.


As a former telephone researcher and call center employee, probably not.

You have to consider that there are two basic types of calls you may be receiving from "telemarketers". There are real "robocalls", where you hear an automated message play. These calls are very common, and are typically used for advertising industries, or scams. The other type of marketing call is where you're in contact with an actual person, albeit a person reading a rather awkward script. These are more frequently used to recruit people for surveys (especially during election periods), or for smaller-scale local advertisement.

If this "hack" works, it almost certainly only works in the first case. Phone numbers are randomly generated for both of these systems, and there is an account created in association with this phone number. Several different "codes" can be applied to numbers in this system, letting employees (or more often, computers) know what to expect. These numbered codes (generally 1-9) are associated with things like interest level, and how aggressively the person reacts to a pitch. The number 9 is generally associated with the option "Do Not Call". In the case of robocalls, the assumption is that by entering a number on the keypad, you are accessing a rotary version of this coding system.

The legitimate "Do Not Call Registry" can be accessed online, and only applies to real "telemarketers" (people trying to sell you things). If you still get calls, the best option is to pick up and clearly say "Please do not call me again. I am not interested. Take my number off your list". This allows anyone on the line, or listening to the recording, to code your response as such, and move on. If you simply hang up, the responses is coded as a "soft refusal", and you will get more calls.

TL;DR: If this hack is true, it still only works for a small number of calls.


In response to the MacK McF post, I believe there is possibly a third type of robocall - the just plain nuisance call where the number is called just to put the receiver of the call to some effort without any intention of the caller having any kind of communication (no response when the phone is answered followed by a quick disconnect).

My other comment is about the numbers being randomly generated. I live in a large city of several million people and get way too many calls to be random. Otherwise each neighbor would be getting a similar amount of calls. This just doesn't happen. I believe numbers are more than likely from a list.

My feeling is that robocalls come generally from one major entity with possibly one or two calls from another source. If the receiver of the call doesn't respond the caller tries caller ID tactic using different caller IDs ex. local prefix and name (I don't know the name of everyone in my city, do you?), VOIP number, random state/city ID (like a person is going to get excited and answer a call from Watts CA or Washington DC), unavailable ID (but sometimes this can be a legit call), some kind of legit org sounding name or initials like MS or DMV. They continue to throw these out there until there is a response.

Being polite and asking to be removed or by pressing 9 simply doesn't do anything. Nothing is generated to a computer for removal. The computers being used are for personal use only and are not connected to some "Do Not Call" database. It all seems to point back to just an individual entity making nuisance calls.

The best method I've found to at least reduce the frequency of robocalls is to use up as much of their time as possible with no possible conclusion for them other than for them to make the disconnect themselves. To do this answer the phone and only make a decently loud enough hum like sound that is intended to activate their sensor and flag your call as active (to get a live person on the other end rather than just the robo connection) then just grunt or groan to their questions until they hang up. DO NOT ever say "yes" or indicate the affirmative as this can be recorded and edited into a bogus recording indicating your approval for a subscription of some kind of service which I've been told can be a lengthy process to get cleared up.


That information is a myth, and some of the previous posts explained it well.

There isn't really a reason to be afraid of your telephones. If you don't want a call, you don't have to answer it.
If you do answer it, just be civil and tell the operator: "Please place this number on your do not call list."
Then wait until the operator acknowledge what you said, it is possible that they did not hear you, in which case they will just call you again.

There are many affordable call blockers available. If you're really worried don't want to speak to a fellow human being, then that's the option for you.

Finally - PLEASE be civil with the operators that call you. They are usually just honest people struggling to make a living.

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