Assigning Numbers to Agents

A phone number must be assigned to an agent before it can handle calls. The assignment links inbound calls on that number to the agent’s AI configuration and sets the number as the caller ID for outbound calls from that agent.

The One-to-One Rule

Each phone number can be assigned to exactly one agent at a time. This keeps call routing simple and predictable:

Inbound calls to the number always go to the same agent
Outbound calls from the agent always show the same caller ID
There is no ambiguity about which agent handles which calls

If you need multiple numbers for the same purpose, create separate agents or assign multiple numbers to a single agent (if your provider supports it).

An agent can exist without a phone number assigned. In that case, the agent can still be used for test calls via the browser but cannot receive inbound calls or make outbound calls.

Assigning from the Phone Numbers Page

Navigate to Phone Numbers in the sidebar
Find the number you want to assign
Click the Assign button or the agent assignment dropdown
Select the agent from the list
Confirm the assignment

Phone number row with agent assignment dropdown

Assign a number to an agent directly from the phone numbers list.

The list only shows agents that are compatible with the number’s provider. A Retell number will only show Retell agents, and so on.

Assigning from the Agent Editor

You can also assign a number while editing an agent:

Navigate to Agents and open the agent you want to configure
Find the Phone Number field in the agent settings
Select an available number from the dropdown
Save the agent

Agent editor with phone number selector dropdown

Assign a phone number while configuring an agent.

The dropdown only shows numbers that match the agent’s provider and are not already assigned to another agent.

💡

Assigning from the Agent Editor is convenient when you are setting up a new agent and want to complete all configuration in one place.

Reassigning a Number

To move a number from one agent to another:

Navigate to Phone Numbers
Find the currently assigned number
Change the agent assignment to the new agent
Confirm the change

The reassignment takes effect immediately. The previous agent will no longer have a phone number and will not be able to receive inbound calls until a new number is assigned.

⚠️

Reassigning a number is instant. Any active inbound routing to the previous agent will switch to the new agent immediately. Make sure the new agent is fully configured before reassigning a production number.

Unassigning a Number

To remove a number from an agent without assigning it elsewhere:

Navigate to Phone Numbers
Find the assigned number
Select Unassign or clear the agent selection
Confirm the change

The number remains in your account but will not route calls to any agent. Inbound calls to an unassigned number will not be answered.

Provider Compatibility

Numbers and agents must use the same voice provider:

Number Provider	Compatible Agents
Retell	Retell agents only
Vapi	Vapi agents only
Bland	Bland agents only

You cannot assign a Retell number to a Vapi agent or vice versa. If you need to switch an agent’s provider, you will need to purchase a new number through the new provider.

Troubleshooting

Verify the number and agent use the same voice provider
Check that the number is not already assigned to another agent
Refresh the page to ensure the latest number list is loaded

Inbound calls are not routing after assignment

Confirm the agent is published and active
Check that the number assignment saved successfully
Verify the provider account is active and the API key is valid
Make a test call to confirm the agent is functioning