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Traffic Type determines how carriers route your messages. Telnyx supports two types: Application-to-Person (A2P) for business messaging and Person-to-Person (P2P) for conversational traffic. Selecting the right type improves deliverability and unlocks features like international SMS.
All new numbers start as A2P by default. After Telnyx monitors your traffic pattern, eligible numbers can be switched to P2P.

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A2P vs P2P Comparison

FeatureA2P (Application-to-Person)P2P (Person-to-Person)
Use caseMarketing, notifications, OTP, alertsConversational, support, 1:1 messaging
Message volumeHigh volume expectedLower volume, more interactive
Domestic SMS✅ Yes✅ Yes
Domestic MMS✅ Yes❌ No
International SMS❌ No (uses alphanumeric fallback)✅ Yes
International MMS❌ No❌ No
Carrier filteringStricter (anti-spam rules apply)More lenient
PricingStandard A2P ratesP2P rates (may differ)
Changing traffic types affects features and pricing. Switching to P2P removes MMS support but enables international outbound SMS.

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When to Use Each Type

Keep A2P

Marketing campaigns, transactional alerts, OTP codes, appointment reminders—any automated business messaging.

Switch to P2P

Support conversations, two-way chat applications, international reach, or use cases requiring a more personal sender profile.
US A2P Messaging: If you’re sending A2P traffic in the United States using 10-digit long codes, you must register your brand and campaigns through 10DLC. Unregistered A2P traffic faces heavy filtering and delivery failures.

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How Eligibility Works

Telnyx monitors your messaging patterns to determine P2P eligibility: The eligible_messaging_products field in the API response shows which options are available for your number.

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Prerequisites

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Check Traffic Type

Retrieve a number’s current traffic type and eligibility using the Messaging Phone Numbers API. 
curl -X GET "https://api.telnyx.com/v2/messaging_phone_numbers/YOUR_PHONE_NUMBER" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY"

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Response Fields

The API response includes key fields for understanding your number’s messaging configuration: 
{
  "data": {
    "phone_number": "+15551234567",
    "messaging_product": "A2P",
    "traffic_type": "A2P",
    "eligible_messaging_products": ["A2P", "P2P"],
    "health": {
      "message_count": 85,
      "inbound_outbound_ratio": 0.43,
      "success_ratio": 0.95,
      "spam_ratio": 0.03
    },
    "features": {
      "sms": {
        "domestic_two_way": true,
        "international_inbound": false,
        "international_outbound": false
      },
      "mms": {
        "domestic_two_way": true,
        "international_inbound": false,
        "international_outbound": false
      }
    }
  }
}
FieldDescription
messaging_productCurrent traffic type (A2P or P2P)
traffic_typeAlias for messaging_product
eligible_messaging_productsAvailable options for this number
health.message_countRecent message volume
health.inbound_outbound_ratioRatio of inbound to outbound messages
health.success_ratioDelivery success rate
health.spam_ratioSpam/block rate
features.smsSMS capabilities by direction
features.mmsMMS capabilities by direction
A low inbound_outbound_ratio (mostly outbound) typically indicates A2P usage, while higher ratios suggest conversational P2P patterns.

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Change Traffic Type

If your number is eligible for both A2P and P2P (check eligible_messaging_products), you can switch between them.
Feature changes take effect immediately. Switching to P2P disables MMS but enables international SMS. Review the comparison table before changing.
curl -X PATCH "https://api.telnyx.com/v2/messaging_phone_numbers/YOUR_PHONE_NUMBER" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{"messaging_product": "P2P"}'

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After Changing to P2P

Your number’s features will update immediately: 
{
  "data": {
    "phone_number": "+15551234567",
    "messaging_product": "P2P",
    "traffic_type": "P2P",
    "features": {
      "sms": {
        "domestic_two_way": true,
        "international_inbound": true,
        "international_outbound": true
      },
      "mms": {}
    }
  }
}
Note that:
  • mms section is now empty (MMS disabled)
  • international_outbound is now true for SMS
  • Pricing may change—check your rate sheet

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International Messaging with P2P

Once your number is configured for P2P, you can send SMS internationally: 
curl -X POST "https://api.telnyx.com/v2/messages" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "from": "+15551234567",
    "to": "+447700900123",
    "text": "Hello from the US!"
  }'
If you try to send internationally from an A2P number, Telnyx will automatically fall back to an alphanumeric sender (like “Telnyx”) where supported.

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Troubleshooting

Cause: Telnyx hasn’t observed enough conversational traffic to qualify the number for P2P.Solutions:
  1. Continue using the number with conversational (two-way) messaging
  2. Wait for the next eligibility review cycle
  3. Contact Telnyx support if you believe your traffic qualifies
Cause: P2P traffic type doesn’t support MMS—this is expected behavior.Solutions:
  1. Switch back to A2P if you need MMS
  2. Use a separate A2P number for MMS messages
  3. For mixed use cases, maintain both A2P and P2P numbers
Cause: Destination country may require sender registration, or the number isn’t fully switched.Solutions:
  1. Verify the number shows messaging_product: "P2P" in the API response
  2. Check if the destination country requires sender pre-registration
  3. Confirm features.sms.international_outbound is true
  4. Review webhook delivery reports for specific error codes
Cause: The number may have lost A2P eligibility based on traffic patterns.Solutions:
  1. Check eligible_messaging_products to confirm A2P is still an option
  2. Contact Telnyx support if A2P eligibility is unexpectedly missing

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Next Steps

Number Pool

Distribute messages across multiple numbers

Rate Limiting

Understand messaging throughput limits

10DLC Registration

Register for A2P 10DLC compliance in the US

Alphanumeric Sender

Send internationally with branded sender IDs