Account owners and admins can manage blocked numbers in the account. Blocked numbers can be incoming (numbers will be blocked from calling in and sending SMS) and outbound (phone users in your account won't be able to dial/text those numbers). You can also block all inbound calls that hide their caller ID. 

Admins can also block incoming external calls for Zoom Rooms and common area phones. For example, since Zoom Rooms and common area phones are often located in public area, you can block all external calls if the room or phone has a direct number and is receiving a lot of spam calls.

Phone users can also manage their own blocked list from the web portal or block a phone number directly from their Zoom app. 

This article covers:

• Limitations of the blocked list
• Effects of blocking calls
• How to manage blocked phone numbers and prefixes for the account (account level)
  • Add block rules for the account
  • Activate or deactivate blocked numbers
  • Delete a blocked number
• How to manage blocked phone numbers, prefixes, and short codes for a phone user (phone user level)
  • Add blocked numbers
  • Delete a blocked number
• How to block callers without a caller ID
  • Account
  • Site
  • Phone user
• How to block external calls 
  • Account
  • Site
  • Phone user, Zoom Room, or common area phone

Prerequisites for blocking calls on Zoom Phone

• Pro, Business, or Education account
• Account owner or admin privileges
• Zoom Phone license 

Limitations of the blocked list

• Blocking phone numbers, prefixes, or callers without a caller ID is available at the account or phone user level. If you have multiple sites, you can't apply block numbers for a specific site.
• Blocking external calls is available at the account, site, or extension (specific phone users, Zoom Rooms, common area phones) levels.
• Blocking external calls only applies to phone users, Zoom Rooms, and common area phones. For example, if you block external calls to the account, only these extensions in the account will be affected.
• Blocking external calls only applies to inbound calls and SMS, meaning outbound calls and SMS to external phone numbers will still be allowed.

Effects of blocking calls

• Blocked calls will not appear in the admin call log and associated phone user's call history.
• Blocked callers will hear a generic message stating that the person they are trying to reach is not available.
• If a phone user calls a blocked outbound phone number, they will hear the same generic message stating that the person they are trying to reach is not available.
• If you blocked numbers at the user level, they can view or change your blocked numbers in their phone settings.
• If you blocked numbers at the account level, phone users can only view (not change) your blocked numbers in their phone settings.

How to manage blocked phone numbers and prefixes for the account (account level)

Add block rules for the account

You can add block rules for all phone users in the account to block a specific number or all numbers with a prefix (country code and area code).

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Phone System Management then Company Info.
3. At the top, click Account Settings.
4. Click the Block List tab.
5. Click Add.
6. Enter the following information:
   
   • Match Type
     • Select Prefix Match if you want to block all numbers with a specific country code and area code.
       Note: Enter a country code as part of the prefix. For example, entering 1905 blocks numbers with country code 1 and area code 905.
     • Select Phone Number Match if you want to block a specific phone number.
       Note: Enter a country code before the prefix or phone number. For example, entering 19051231234, blocks number +1 (905) 123-1234.
   • Type
     • Select Inbound to prevent the blocked number or prefix from calling/texting phone users.
     • Select Outbound to prevent phone users from calling the blocked number or prefix.
   • Comment (optional): Enter a comment to help you identify the blocked number or prefix.
   • Status: Enable or disable the blocked number.
7. Click Save.

Activate or deactivate blocked numbers

After adding numbers to the Block List, you can activate or deactivate them. Deactivated blocked numbers will appear but won't apply to any outbound or inbound calls until activated.

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Phone System Management, then Company Info.
3. At the top, click Account Settings.
4. Click the Block List tab.
5. To the right of the rule you want to activate or deactivate, click Edit.
6. Click the Status toggle to activate the blocked number (enable) or deactivate it (disable).
7. Click Save.

Delete a blocked number

You can delete numbers from your block list if you don't want to block that number. You can only delete numbers or rules one at a time.

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Phone System Management, then Company Info.
3. At the top, click Account Settings.
4. Click the Block List tab.
5. To the right of the rule you want to remove, click Delete.
   A confirmation window will appear.
6. In the window, click Delete to confirm.

How to manage blocked phone numbers, prefixes, and short codes for a phone user (phone user level)

Follow these steps if you only want block rules to apply to a specific user.

Add blocked numbers

Note: Each phone user can view or change these blocked numbers in their phone settings. Block numbers applied to the entire account will still apply to the phone user if you set user-specific block rules.

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Phone System Management, then Users & Rooms.
3. Click the name of the user you want to block numbers for.
   Note: You can only block numbers for phone users, not Zoom Rooms added to Zoom Phone.
4. Click User Settings.
5. Under Others, in the Block List section, click Manage Block List to block specific phone numbers, prefixes, or SMS short codes.
6. Customize these settings:
   1. Click Manage Block List.
      Blocked prefixes and numbers that apply to all users are displayed beside Default.
   2. Click Add in one of the following sections to block prefixes, numbers, or extensions:
      • Blocked phone number prefixes: To the right of Blocked Prefixes, click Add to block all numbers with a specific country code and area code. Select an area code, enter a prefix, and click Save.
        For example, entering 1905 blocks numbers with country code 1 and area code 905.
      • Blocked numbers: To the right of Blocked Numbers, click Add to block a specific phone number. Select an area code, enter a phone number, and click Save.
        For example, entering 19051231234, blocks number +1 (905) 123-1234.
      • Blocked SMS short codes: To the right of Blocked SMS short codes, click Add to block a specific SMS short code. Select an SMS short code number and click Save.
        For example, entering 5 or 6-digit phone number used to send mass text messages, such as 236-56, blocks SMS short code 23656.

Delete a blocked number

You can delete numbers from your block list if you don't want to block that number. You can only delete numbers or rules one at a time.

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Phone System Management, then Users & Rooms.
3. Click the name of the user you want to block numbers for.
4. Click User Settings.
5. In the Block List section, click Manage Block List.
6. To the right of Blocked Prefixes, Blocked Numbers, or Blocked SMS Short Codes, click × next to the blocked number, prefix, or SMS short code you want to delete.

How to block callers without a caller ID

Enable or disable Block Calls without Caller ID to block all incoming callers that hide their caller ID.

Account

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Account Management then Account Settings.
3. Click the Zoom Phone tab.
4. Under General, click the Block Calls without Caller ID toggle to enable or disable it.
5. If a verification dialog displays, click Enable or Disable to verify the change.
6. (Optional) To prevent all users in your account from changing this setting, click the lock icon , and then click Lock to confirm the setting.

Site

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Phone System Management, then Company Info.
3. Click the name of the site you want to edit.
4. Click the Policy tab.
5. Under General, click the Block Calls without Caller ID toggle to enable or disable it.
6. If a verification dialog displays, click Enable or Disable to verify the change.
7. (Optional) To prevent all users in your account from changing this setting, click the lock icon , and then click Lock to confirm the setting.

Phone user

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Phone System Management, then Users & Rooms.
3. Click the name of the user you want to block numbers for.
4. Click User Settings.
5. Under Others, in the Block List section, click the Block Calls without Caller ID toggle to enable or disable it.
6. If a verification dialog displays, click Enable or Disable to verify the change.

How to block external calls 

You can also block all inbound external calls at the account, site, or extension (specific phone users, Zoom Rooms, common area phones) level. Blocking external calls only applies to inbound calls/SMS, meaning outbound calls/SMS to external phone numbers will still be allowed. This setting only applies to incoming calls. Phone users can still call external phone numbers.

Notes:

• Blocking external calls only applies to phone users, Zoom Rooms, and common area phones. If you block external calls at the account level, only these extensions in the account will be affected.
• External calls include all calls from phone numbers that are:
  • not direct Zoom Phone numbers in the same account
  • not configured as part of BYOC
  • not synchronized from Exchange or Active Directory
  • not Zoom user's personal phone number

Account

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Account Management then Account Settings.
3. Click the Zoom Phone tab.
4. Under General, click the Block External Calls toggle to enable or disable it.
5. If a verification dialog displays, click Enable or Disable to verify the change.
6. (Optional) To prevent all users in your account from changing this setting, click the lock icon , and then click Lock to confirm the setting.
7. Set rules for blocking external calls during the following hours:
   • Business hours: Select whether to apply the rule during the affected extension's business hours.
   • Closed Hours: Select whether to apply the rule during the affected extension's closed hours.
   • Holiday Hours: Select whether to apply the rule during the affected extension's holiday hours.
   • When a call is blocked: Route blocked calls to the affected extension's voicemail, or immediately disconnect the call.
8. Click Save.

Site

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Phone System Management, then Company Info.
3. Click the name of the site you want to edit.
4. Click the Policy tab.
5. Under General, click the Block External Calls toggle to enable or disable it.
6. If a verification dialog displays, click Enable or Disable to verify the change.
7. (Optional) To prevent all users in your account from changing this setting, click the lock icon , and then click Lock to confirm the setting.
8. Set rules for blocking external calls during the following hours:
   • Business hours: Select whether to apply the rule during the affected extension's business hours.
   • Closed Hours: Select whether to apply the rule during the affected extension's closed hours.
   • Holiday Hours: Select whether to apply the rule during the affected extension's holiday hours.
   • When a call is blocked: Route blocked calls to the affected extension's voicemail, or immediately disconnect the call.
9. Click Save.

Phone user, Zoom Room, or common area phone

1. Sign in to the Zoom web portal.
2. In the navigation menu, click Phone System Management, then Users & Rooms.
3. Click the Users, Zoom Rooms, or Common Area Phones tab depending on what extension you want to edit.
4. Click the name of the extension you want to edit.
5. Click the User Settings or Settings tab.
6. In the Block Rules section, click the Block External Calls toggle to enable or disable it.
7. If a verification dialog displays, click Enable or Disable to verify the change.
8. Set rules for blocking external calls during the following hours:
   • Business hours: Select whether to apply the rule during the affected extension's business hours.
   • Closed Hours: Select whether to apply the rule during the affected extension's closed hours.
   • Holiday Hours: Select whether to apply the rule during the affected extension's holiday hours.
   • When a call is blocked: Route blocked calls to the affected extension's voicemail, or immediately disconnect the call.
9. Click Save.