Discover how our products can revolutionize the way you communicate and collaborate.


Explore our advanced voice solutions designed to optimize your communication workflows.

Diverse range of DID number solutions designed to enhance your communication capabilities.

Experience unparalleled communication efficiency with our advanced SIP Trunking Solutions.

Cutting-edge technology to proactively detect and neutralize spam flags on your DID Numbers.


Wherever your audience is, our platform ensures seamless messaging across diverse channels.

Build customer journeys by fostering interactive conversations, all within the framework of your app. 

Connect with your audience in a simple and effective way through our cutting-edge SMS platform. 


Harness the power of IDT as your chosen carrier while leveraging your platform’s advanced features and services.

Integrate Twilio with our robust carrier routing platform to achieve unparalleled Voice termination system.

Experience reliable and high-quality communication services while leveraging the advanced capabilities of Genesys. 

Integrate IDT with the collaborative strength of MS Teams, unlocking efficient and feature-rich communication. 

Experience the power of our carrier network seamlessly connected to Plivo through our cutting-edge BYOC solution. 


Experience the power of our online voice tools, designed to simplify communication management. 

Ensure the authenticity and integrity of outbound calls with our STIR/SHAKEN Verification Check tool. 

User-friendly tool to verify the reputation of your business number, ensuring that it remains trusted. 

Compare and gain insights into outbound call expenses, optimize budget, and make informed decisions. 

Easily estimate and compare the costs associated with different DID numbers providers. 

Compare inbound VoIP rates among top CPaaS providers and optimize your inbound call costs. 

Generate custom SMS templates. 


Empower yourself with the resources you need to thrive in the dynamic landscape of communication.

Articles covering a wide range of topics.

Get answers to common queries.

Find instructions to make the most of our products.

Discover telecom insights and trends.

Find definitions of popular telecom terms.

Explore how our solutions have helped businesses.

Latest telecom trends, innovations, and market insights.


A global telecom partner built to meet your needs. 

Discover the story behind our commitment to delivering innovative solutions to connect people and businesses worldwide. 

Learn about our robust network infrastructure that spans across the globe, ensuring reliable and secure connectivity. 

Got a question, feedback, or need assistance? Our dedicated team is here to help!

Find partners or sign up for partnership programs.



In this article

A blocklist refers to a list of phone numbers or contacts that have been flagged or identified as undesirable recipients for SMS messages. These numbers may belong to recipients who have explicitly requested not to receive SMS messages from the sender, or they may be identified as invalid, spam, or potential threats.

Businesses maintain blocklists as part of their SMS marketing or communication strategies to ensure compliance with regulations, respect recipient preferences, and protect their reputation. By regularly updating and managing blocklists, businesses can avoid sending unwanted messages to recipients who are not interested or have opted out of receiving SMS communications.

Overall, blocklists play a crucial role in maintaining the effectiveness and legitimacy of B2B SMS campaigns by helping businesses target their messages more effectively and avoid potential legal or reputational issues associated with unsolicited messaging.

How to avoid getting blocklisted?

To avoid getting blocklisted, try:

  • Obtain explicit consent from recipients before sending SMS messages.
  • Provide clear opt-in and opt-out mechanisms for recipients.
  • Honor opt-out requests promptly and accurately.
  • Avoid sending unsolicited or irrelevant messages.
  • Monitor and manage message frequency to prevent spamming.
  • Use legitimate and identifiable sender IDs.
  • Ensure compliance with relevant regulations, such as GDPR or TCPA.
  • Regularly update and maintain clean contact lists.
  • Respect recipient preferences and privacy concerns.
  • Monitor and respond to feedback and complaints from recipients.

What is the difference between a Blocklist and a Do Not Disturb (DND) list?

The difference between a Blocklist and a Do Not Disturb (DND) list lies in their purposes and functionalities:


1. Purpose: A blocklist is a list of phone numbers or contacts that have been flagged or identified as undesirable recipients for SMS messages.

2. Functionality: Numbers on the blocklist are typically prevented from receiving any messages from the sender, regardless of the content or sender’s intent.

3. Usage: Blocklists are used by businesses to avoid sending messages to recipients who have explicitly requested not to receive communications, or to filter out invalid, spam, or potentially harmful numbers.

Do Not Disturb (DND) list:

1. Purpose: A Do Not Disturb (DND) list is a list of phone numbers registered by recipients who do not wish to receive unsolicited marketing or promotional messages.

2. Functionality: Numbers on the DND list are legally protected from receiving promotional messages, but they may still receive transactional or service-related messages if they have consented to them.

3. Usage: DND lists are maintained and regulated by telecommunication authorities or regulatory bodies to protect consumer privacy and prevent unwanted messages. Businesses must comply with DND regulations and refrain from sending promotional messages to numbers on the DND list.

Share this article

Meet our wholesale voice routing

Fulfill all your voice calling needs with our category leading wholesale A-Z Voice Termination.
Try IDT Express for a $25 Credit

Get $25 Free Trial Credit

You could be interested in


DLR (Delivery Reporting)

Delivery reporting is a feature of SMS MT that reports back on the delivery status...

One-Time PIN Code

In today's digital world, security is of paramount importance. With the increasing reliance on online...

MNO (Mobile Network Operator)

A Mobile Network Operator (MNO), also known as a wireless carrier or mobile operator, is...