Spam Monitoring and Phone Number Health docs (#485)

Author: AdiSai

fern/calls/call-outbound.mdx

@@ -6,7 +6,7 @@ slug: calls/outbound-calling
 
 ## Introduction to Outbound Calling
 
-Vapi’s outbound calling API lets you programmatically initiate single or batch calls to any phone number. You can schedule calls for specific dates and times, ideal for time-sensitive communications. Easily integrate outbound calling into your app for appointment reminders, automated surveys, and call campaigns.
+Vapi's outbound calling API lets you programmatically initiate single or batch calls to any phone number. You can schedule calls for specific dates and times, ideal for time-sensitive communications. Easily integrate outbound calling into your app for appointment reminders, automated surveys, and call campaigns.
 
 ## Prerequisites
 
@@ -83,7 +83,7 @@ Use both `customers` and `schedulePlan` together to schedule batched calls.
 Use the [`example template`](/assets/batch-sample.csv) to get started.
 
 * The only required columns are **`phone`** and **`name`**.
-* Any other columns (like `appointment_time`, `location`, etc.) can be used as dynamic variables in your assistant’s script.
+* Any other columns (like `appointment_time`, `location`, etc.) can be used as dynamic variables in your assistant's script.
 
 ## How to Launch a Batch Call
 
@@ -200,6 +200,63 @@ Beyond CNAM registration, registering with major caller reputation databases hel
 3. Submit business profile and branding information
 4. Monitor your caller reputation through their dashboard
 
+### Spam Monitoring and Phone Number Health
+
+Proactive monitoring of your phone number reputation is essential to maintain high answer rates and prevent spam labeling. Several tools and services can help you track and remediate spam labels before they impact your campaigns.
+
+#### Twilio Voice Integrity
+
+[Twilio Voice Integrity](https://www.twilio.com/docs/voice/spam-monitoring-with-voiceintegrity) helps remediate spam labels on your phone numbers and monitor their reputation across major carrier networks.
+
+**What Voice Integrity provides:**
+- **Spam label remediation** for T-Mobile, Sprint, and AT&T networks
+- **Reputation monitoring** across carrier analytic engines
+- **Automatic registration** of your Twilio phone numbers with carrier databases
+- **Integration with Trust Hub** for streamlined verification
+
+**Getting started with Voice Integrity:**
+
+<Steps>
+  <Step title="Meet prerequisites">
+    - Ensure you have an approved Primary Customer Profile in Trust Hub
+    - For ISVs: obtain approved secondary customer profiles for tenants
+  </Step>
+  
+  <Step title="Register through Trust Hub">
+    - Access Voice Integrity through your Twilio Console
+    - Complete the registration process via Trust Hub REST API or console
+    - Your numbers will be automatically registered with carrier analytic engines
+  </Step>
+  
+  <Step title="Monitor and maintain">
+    - Voice Integrity will automatically work to remediate spam labels
+    - Future updates will include reputation monitoring and degradation alerts
+    - Verizon Wireless integration coming soon (automatic for existing users)
+  </Step>
+</Steps>
+
+<Note>
+Voice Integrity works best when combined with STIR/SHAKEN attestation, as the highest level of attestation signals to analytic engines that you're a legitimate caller.
+</Note>
+
+#### External Phone Number Health Monitoring
+
+In addition to carrier-provided services, external monitoring APIs can help you proactively check your phone number reputation across different networks and spam databases.
+
+**Recommended monitoring services:**
+
+**IPQualityScore Phone Number Validation**
+- **Service**: [IPQualityScore](https://www.ipqualityscore.com/) provides comprehensive phone number reputation scoring
+- **Features**: Real-time spam risk assessment, carrier identification, line type detection
+- **Use case**: Check numbers before campaigns and monitor reputation changes
+- **Integration**: REST API for batch checking or real-time validation
+
+**Nomorobo Spam Database**
+- **Service**: [Nomorobo](https://www.nomorobo.com/) maintains one of the largest spam phone number databases  
+- **Features**: Spam reputation lookup, robocall identification, carrier reporting
+- **Use case**: Verify if your numbers are flagged in spam databases
+- **Integration**: API access for reputation checking
+
 ### Best Practices for Trusted Calling
 
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