> For the complete documentation index, see [llms.txt](https://help.stringeex.com/stringeex-tong-dai-cham-soc-and-quan-ly-khach-hang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://help.stringeex.com/stringeex-tong-dai-cham-soc-and-quan-ly-khach-hang/en/ii.-system-features/9.-settings/9.1-service-management-customer-service/9.1.4-configure-receiving-channels/channels/blacklist-numbers.md). # Blacklist numbers Blocked numbers are numbers that are in the blacklist of the system and will be blocked from calling out or blocking inbound calls (IVR or Queue).

To add a number to the user block list, click the "Add block number" button on the interface:

There are two ways to add numbers to the block list: * **Enter the phone number manually:** the user enters the phone number he wants to block according to the form on the system.

Image 3: Enter the phone number in need of blocking

* **Upload block list file:** users download the system's sample file in Excel format, then enter the list of numbers to block and upload to the system.

Image 4: Download the file list of phone numbers to block

When adding numbers to the block list, users will have options to block numbers that match the desired purpose and requirements:

* **(1) Blocking into the IVR tree:** blocked subscribers cannot call into the system and be included in the IVR. * **(2) Blocking into queue:** blocked subscribers can still call in and be included in IVR but will be disconnected as soon as time in IVR expires. * **(3) Blocking out calls:** all users on Portal cannot use any hotline numbers to call out to blocked subscribers.