Kaleyra Blocklist or Blocked numbers are the list of recipient phone numbers that have been blocked from sending any SMS and Voice messages from the Brand through This typically prevents unwanted communications from reaching the recipients and allows only useful SMS messaging and calls.

The key features of using Kaleyra Blocklist are:

  • Targets preferred channels.
  • Prevents legal disputes.
  • Lowers costs by ensuring deliverability.

Use case:

The following are the use cases used:

  • Enforce compliance measures by preventing outgoing messaging to particular contacts (for example, unwanted communication).
  • Reduce costs by preventing the sending of messages to known ineligible contacts or non-registered devices.

How Blocklist Works

Blocklists are more advanced than opt-outs by ensuring nothing is delivered to a Blocklisted contact until the Brand itself removes the contact from the Blocklist. Instead of Blocking a contact from all forms of communication, you can select a specific channel(s) to Block unwanted communication from being delivered on that specific channel. The Blocklist feature supports the Blocking of SMS messaging and Voice calling. This feature enables Brands to streamline promotional messaging through their subscriber’s preferred channels. There are two methods of channel specific Blocklisting, which are individually or in bulk. You may Block an individual contact when creating or editing the contacts in the Directory service, or a group of contacts when importing a .csv file in the Directory service. Once a contact is added to the Blocklist, no messages or calls will be delivered to that recipient. By carrying out the reverse operation, you can also Unblock contacts individually or in bulk.

For more information about the Blocklist feature, see the following topics: