Cloud Business Phone Systems
CoreNexa cloud phones for Phoenix-metro businesses — desk phones, mobile and desktop apps, and a customer portal you control.
A phone system that goes wherever your team goes
C13 provides cloud business phone service on the CoreNexa platform. Your phone system lives in the cloud instead of a box in the back closet, so there's no on-site PBX to maintain. Calls can ring desk phones, cell phones and computers — all using your business number and caller ID.
- Make and receive calls with your business caller ID from desk phone, mobile app or computer
- Auto attendant / virtual receptionist with day, night and holiday schedules
- Voicemail with greetings you can update from the app
- Extension dialing and a shared company directory
- Ring groups, call queues and call forwarding
- Conference bridges and video meetings
- Manage it all from the customer portal
Customer Portal
Manage users, voicemail, forwarding, auto attendant schedules and greetings for your account.
Customer Portal Sign InOpens cloud.c13usa.com. Forgot your login? Call (480) 397-2627.
Download the CoreNexa app
Take your business line with you. Install the official CoreNexa app, then sign in with your C13 portal username and password.
1. Download
iPhone/iPad: App Store (listed as “CoreNexa Legacy”). Android: Google Play (“CoreNexa”). Computer: the desktop download page detects Windows, Mac or Linux.
2. Sign in
Use the same username and password as the customer portal at cloud.c13usa.com. Installing the desktop app on Windows may require administrator rights.
3. Allow permissions
Allow microphone, notifications and contacts so calls ring reliably and your directory works. Need help? Call (480) 397-2627.
Links go to the official CoreNexa, LLC listings on the Apple App Store and Google Play, and CoreNexa's desktop download page. App names and availability are controlled by CoreNexa.
Moving from an older phone system?
Many cloud customers come from Nortel Norstar, Allworx or Avaya systems. We can keep your current system running while we plan the move, port your numbers, reuse cabling where it makes sense, and train your staff on day one. Legacy phone support →
Cloud phone FAQ
How do I sign in to the CoreNexa app?
Download CoreNexa for your device, open it and sign in with the same username and password you use for the C13 customer portal at cloud.c13usa.com. If you don't have a login yet, call C13 and we'll set one up.
Can I keep my existing business phone numbers?
In most cases, yes. Numbers are usually ported from your current carrier; C13 coordinates the port so your numbers move over on a scheduled date.
Do I need new desk phones?
Not always. Some users only need the mobile or desktop app. Where desk phones make sense, we'll recommend compatible models and program them for you.
What do I need for internet?
A reliable business internet connection with enough upload bandwidth for your call volume. We can review your network and cabling before switching over.