# Purchase a DID on CM.com Platform

Before you can place or receive calls, you must have at least **one active DID** (or multiple DID numbers) on your **CM.com** account.

> **Note**\
> If you already have active DID numbers on your CM.com account, you can skip this section and proceed directly to trunk configuration.

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### Create Your CM.com Account

1. Visit the [CM.com ](/portsip-communications-solution/configuring-sip-trunks/cm.com-sip-trunk.md)website and sign up for an account.
2. After logging in, ensure that voice services (SIP trunking) are enabled for your account.

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### Purchase DID Numbers

1. In the [CM.com](/portsip-communications-solution/configuring-sip-trunks/cm.com-sip-trunk.md) portal, follow the guide [How do I order a new DDI number?](https://knowledgecenter.cm.com/knowledge-center/communications-platform/sip-trunking/ddi-numbers/how-do-i-order-a-new-ddi-number)  to purchase the DID numbers.

After the DID numbers are successfully purchased and activated, you can proceed with configuring the [CM.com](/portsip-communications-solution/configuring-sip-trunks/cm.com-sip-trunk.md) SIP trunk in PortSIP PBX.

***

### Next Step

* [Configure CM.com IP Authentication Trunk](/portsip-communications-solution/configuring-sip-trunks/cm.com-sip-trunk/configuring-cm.com-ip-authentication-trunk.md)
* [Configure CM.com Register Authentication Trunk](/portsip-communications-solution/configuring-sip-trunks/cm.com-sip-trunk/configuring-cm.com-register-authentication-trunk.md)

This step configures PortSIP PBX to use CM.com for outbound and inbound calling.


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