Get missed‑call, voicemail & text notifications in Slack.

Numberline posts each notification to the Slack channel you choose. Open Numberline to call or text back from your business number.

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Channel per extension · Voicemail notifications · New text alerts

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Choose a Slack channel for each extension.

Pick which events post and where they go. Turn Slack off for any extension.

Slack notifications
Missed calls
#calls
New sales texts
#sales
Support voicemails
#support
Voicemail for Bob
#bob
Per-extension controls
Extension 1Sales#sales
Missed callsNew textsVoicemails
Extension 2Support#support
Missed callsNew textsVoicemails
Extension 3Bob#bob
Missed callsNew textsVoicemails
Extension 4BillingSlack off
Missed callsNew textsVoicemails

See it in Slack. Call or text back in Numberline.

Each post says who reached you and which extension they chose.

NumberlineAPP10:42 AM

Missed call · Dana M. · Ext 1 Sales

Rang your mobile and Rosa’s mobile. No voicemail left.

Call back in Numberline

Missed call

Who called, which extension, and when. Call back from your business number in Numberline.

NumberlineAPP11:07 AM

New text · (512) 555-0148 · Ext 1 Sales

“Hi, do you have availability Thursday for a quote on a new water heater?”

#salesReply in Numberline

New text

A preview of the message in that extension’s channel. Reply from the shared inbox.

NumberlineAPP3:26 PM

New voicemail · Priya S. · Ext 2 Support

New voicemail, 0:24. Open Numberline to listen, read the transcript, and call back.

Voicemail notification

Who left a voicemail and for which extension. Open Numberline to listen, read the transcript, and call back.

Learn how business texting and voicemail delivery work.

Route calls by extension. Get the notifications in Slack.

Extensions ring your team’s mobiles or your own AI agent from Vapi or another provider. Texts and WhatsApp land in the shared inbox.

Learn how call forwarding and AI agent connections work.

Frequently asked questions

How does the Slack integration work?
Connect your Slack workspace and choose which events post where. Numberline posts missed-call, voicemail, and new-text notifications into the channels you pick. Open Numberline to read the message and call back.
Can different extensions post to different channels?
Yes. Sales voicemails can post to #sales and Support voicemails to #support. Each extension chooses which events post, or turns Slack off.
Can I reply from Slack?
Replies happen in the Numberline app. Call back or text from your business number. Customers see your business caller ID.
Is Slack required?
No. Every call, text, and voicemail is in the Numberline app. Each voicemail is emailed to you with the recording, a transcript, and an AI summary. Turn Slack on when your team wants it.
Do you charge per user?
No. Users are unlimited. Add teammates, assistants, and contractors without another seat fee.
Do I need new phones or equipment?
No. Numberline forwards calls to the mobile you already have. The app runs on the same phone.

Connect your business number to Slack.

Alerts in the channels your team watches.

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No per-user fees No long-term contracts 30-day money-back guarantee