Phone Number Documentation

Why You Need a Phone Number

Every voice agent needs at least one phone number to make or receive calls. The phone number serves as the agent's identity on the telephone network — it is the number that appears on the recipient's caller ID for outbound calls and the number people dial to reach your agent for inbound calls.

You can assign multiple agents to different numbers, or use the same number for multiple purposes (for example, outbound campaigns during business hours and an AI receptionist after hours). Phone numbers are managed at the organization level and can be reassigned between agents at any time.

Getting a Number from the CallTone Pool

The fastest way to get started is to provision a number from the CallTone pool. These are US local numbers that are pre-registered and ready for immediate use.

To provision a number, navigate to Dashboard > Phone Numbers and click Get a Number. You can search by area code or state to find a number local to your business or your target audience. Select a number and click Provision to add it to your account.

Key benefits of CallTone pool numbers:

Instant activation — Numbers are ready to use within seconds. No waiting for carrier provisioning or registration.
A2P 10DLC pre-registered — All pool numbers are pre-registered for Application-to-Person (A2P) messaging under the 10DLC framework, ensuring reliable SMS delivery for appointment confirmations, missed call text-backs, and other automated messages.
Voice and SMS capable — Every number supports both voice calls and SMS messaging out of the box.
STIR/SHAKEN verified — Numbers carry attestation to reduce the likelihood of calls being flagged as spam by carrier networks.

Pool numbers are included in your subscription at no additional per-number cost. The number of phone numbers you can provision depends on your plan tier (Starter: 1, Growth: 5, Business: 25, Enterprise: unlimited).

Importing a Number from Twilio

If you already own phone numbers through Twilio, you can import them into CallTone to use with your voice agents. This lets you keep your existing numbers and caller ID reputation.

To import a Twilio number:

Go to Dashboard > Phone Numbers and click Import from Twilio.
Enter your Twilio Account SID and Auth Token. These are found on your Twilio Console dashboard. CallTone uses these credentials to fetch your number inventory and configure call routing.
CallTone will display a list of phone numbers on your Twilio account. Select the number(s) you want to import.
Click Import. CallTone will configure the Twilio number's voice webhook to route incoming calls through CallTone. Your Twilio account continues to own the number; CallTone simply handles the call routing.

Imported numbers continue to be billed through your Twilio account. CallTone does not charge additional fees for imported numbers, but standard per-minute call charges from your CallTone plan still apply.

Assigning Numbers to Agents

After provisioning or importing a number, you need to assign it to a voice agent. A number must be assigned to an agent for inbound calls to be answered. For outbound calls and campaigns, you select the number during campaign setup.

To assign a number:

Go to Dashboard > Phone Numbers, find the number, and click Assign Agent. Select the agent from the dropdown.
Alternatively, go to the agent's settings page and assign a phone number in the Phone Number section.

A single phone number can only be assigned to one agent at a time for inbound call routing. However, multiple agents can use the same number for outbound calls within different campaigns.

Caller ID Configuration (CNAM)

CNAM (Calling Name) is the name that appears on the recipient's phone when they receive a call from your number. Setting a professional CNAM increases the likelihood that recipients answer the call.

To configure CNAM, go to Dashboard > Phone Numbers, click on the number, and enter a display name in the Caller ID Name field.

CNAM is limited to 15 characters maximum, including spaces. Choose a concise business name or abbreviation.
CNAM updates can take 24–72 hours to propagate across all carrier networks. The name may not appear immediately or consistently on all devices.
Not all carriers display CNAM. Mobile carriers in particular may not show the caller name, only the number.
Use your real business name. Misleading CNAM values may violate FCC regulations and could result in your number being flagged as spam.

A2P 10DLC Compliance

A2P 10DLC (Application-to-Person 10-Digit Long Code) is a regulatory framework required by US carriers for businesses sending SMS messages from local phone numbers. Non-compliant messages may be blocked or filtered by carriers.

CallTone simplifies A2P compliance:

Pool numbers are pre-registered — Phone numbers from the CallTone pool are already registered under CallTone's approved A2P brand and campaign. You can start sending SMS (appointment reminders, missed call text-backs) immediately without additional registration steps.
Twilio-imported numbers — If you import a Twilio number, SMS messages are sent through your Twilio account using your existing A2P registration. Ensure your Twilio number is registered for A2P messaging in your Twilio Console.
Message throughput — A2P 10DLC provides higher SMS throughput (typically 75–300 messages per second) compared to unregistered numbers, ensuring your appointment confirmations and notifications are delivered promptly.

Releasing Numbers

If you no longer need a phone number, you can release it back to the pool:

Ensure the number is not assigned to any active agent or campaign. If it is, unassign it first.
Go to Dashboard > Phone Numbers, click the number, and select Release Number.
Confirm the release. The number will be removed from your account immediately.

Released pool numbers are returned to the CallTone inventory and may be provisioned by another customer. You cannot guarantee you will get the same number back if you release it. For Twilio-imported numbers, releasing removes the CallTone webhook configuration but does not delete the number from your Twilio account.

Call history and recordings associated with a released number are retained in your account for your configured data retention period. Releasing a number does not delete any historical data.