Telnyx

Sole Proprietor registration enables individuals and small businesses without a federal Tax ID (EIN) to register for 10DLC messaging. This guide covers the API workflow for creating Sole Proprietor brands, completing OTP verification, and managing campaigns programmatically.

Overview

Sole Proprietor brands have specific constraints compared to standard business brands:

Constraint	Limit
Campaigns per brand	1
Phone numbers per campaign	1
Mobile phone reuse	Max 3 SP brands per mobile number
Throughput	Low-volume (varies by carrier)

Sole Proprietor registration requires identity verification via SMS OTP before campaigns can be created.

Prerequisites

Telnyx account with API access
At least one US 10DLC phone number
Valid US/CA mobile phone number for OTP verification
Personal information: name, address, date of birth

Registration Flow

Step 1: Create a Sole Proprietor Brand

Create a brand with entityType set to SOLE_PROPRIETOR:

Valid vertical values include: PROFESSIONAL, REAL_ESTATE, HEALTHCARE, RETAIL, ENTERTAINMENT, EDUCATION, NONPROFIT, GOVERNMENT, and others. See the Brand API Reference for the full list.

curl -X POST https://api.telnyx.com/v2/10dlc/brand \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "entityType": "SOLE_PROPRIETOR",
    "firstName": "Jane",
    "lastName": "Smith",
    "displayName": "Jane Smith Consulting",
    "email": "[email protected]",
    "phone": "+12025551234",
    "mobilePhone": "+12025559876",
    "street": "123 Main St",
    "city": "Austin",
    "state": "TX",
    "postalCode": "78701",
    "country": "US",
    "vertical": "PROFESSIONAL"
  }'

Response

{
  "brandId": "f5586561-8ff0-4291-a0ac-84fe544797bd",
  "entityType": "SOLE_PROPRIETOR",
  "displayName": "Jane Smith Consulting",
  "firstName": "Jane",
  "lastName": "Smith",
  "identityStatus": "PENDING",
  "mobilePhone": "+12025559876",
  "createdAt": "2026-02-03T12:00:00Z"
}

The brand will remain in PENDING identity status until OTP verification is completed. You cannot create campaigns until the brand is VERIFIED.

Step 2: Trigger OTP Verification

Send an OTP PIN to the mobile phone associated with the brand:

curl -X POST https://api.telnyx.com/v2/10dlc/brand/{brand_id}/smsOtp \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "pinSms": "Your Telnyx verification code is @OTP_PIN@. This code expires in 24 hours.",
    "successSms": "Your Telnyx 10DLC brand has been verified successfully."
  }'

Request Parameters

Parameter	Type	Required	Description
`pinSms`	string	Yes	SMS message containing `@OTP_PIN@` placeholder (max 500 chars)
`successSms`	string	Yes	Confirmation SMS sent after successful verification (max 500 chars)

Response

{
  "brandId": "f5586561-8ff0-4291-a0ac-84fe544797bd",
  "referenceId": "OTP8A3B2C"
}

The @OTP_PIN@ placeholder in pinSms will be replaced with the actual 6-digit PIN when the SMS is sent.

Step 3: Check OTP Status

Poll the OTP status to confirm delivery:

curl -X GET https://api.telnyx.com/v2/10dlc/brand/{brand_id}/smsOtp \
  -H "Authorization: Bearer YOUR_API_KEY"

Response

{
  "brandId": "f5586561-8ff0-4291-a0ac-84fe544797bd",
  "referenceId": "OTP8A3B2C",
  "mobilePhone": "+12025559876",
  "requestDate": "2026-02-03T12:05:00Z",
  "verifyDate": null,
  "deliveryStatus": "DELIVERED_HANDSET",
  "deliveryStatusDate": "2026-02-03T12:05:02Z",
  "deliveryStatusDetails": "Delivered to handset"
}

Delivery Status Values

Status	Description
`PENDING`	OTP request submitted, awaiting delivery
`DELIVERED_HANDSET`	SMS delivered to the mobile device
`DELIVERY_FAILED`	SMS delivery failed
`VERIFIED`	OTP PIN successfully verified
`EXPIRED`	OTP PIN expired (24-hour window)

Step 4: Verify OTP PIN

After the user receives and provides the PIN, verify it:

curl -X POST https://api.telnyx.com/v2/10dlc/brand/{brand_id}/smsOtp/verify \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "otpPin": "123456"
  }'

Upon successful verification:

The brand identityStatus changes to VERIFIED
The successSms message is sent to the mobile phone
The brand registration fee is charged
You can now create campaigns

Step 5: Create a Sole Proprietor Campaign

With a verified brand, create a campaign using the SOLE_PROPRIETOR usecase:

Sample messages (sample1, sample2) are required for campaign approval. Include realistic examples of messages you’ll send.

curl -X POST https://api.telnyx.com/v2/10dlc/campaignBuilder \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "brandId": "f5586561-8ff0-4291-a0ac-84fe544797bd",
    "usecase": "SOLE_PROPRIETOR",
    "description": "Customer appointment reminders and booking confirmations for consulting services.",
    "messageFlow": "Customers opt-in via web form when booking appointments. They receive confirmation and reminder messages.",
    "helpMessage": "Reply HELP for assistance. Contact [email protected]",
    "optoutMessage": "Reply STOP to unsubscribe from messages.",
    "sample1": "Hi Jane, this is a reminder of your appointment tomorrow at 2pm.",
    "sample2": "Your booking for March 15th has been confirmed. Reply STOP to opt out.",
    "termsAndConditions": true
  }'

Response

{
  "campaignId": "c5e5e598-95b3-4076-bfe2-c7d2c58ec57f",
  "brandId": "f5586561-8ff0-4291-a0ac-84fe544797bd",
  "usecase": "SOLE_PROPRIETOR",
  "status": "ACTIVE",
  "description": "Customer appointment reminders and booking confirmations for consulting services.",
  "createdAt": "2026-02-03T12:30:00Z"
}

Sole Proprietor campaigns are typically auto-approved and become ACTIVE immediately. Standard campaigns may require carrier review.

Step 6: Assign a Phone Number

Assign your 10DLC number to the campaign:

curl -X POST https://api.telnyx.com/v2/10dlc/phone_number_campaigns \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "phoneNumber": "+12025551234",
    "campaignId": "campaign_id_here"
  }'

Sole Proprietor campaigns can only have one phone number assigned. Attempting to assign additional numbers will return an error.

Error Handling

Common Errors

Error	Cause	Solution
`Sole Proprietor brands can only have one active campaign`	Attempting to create a second campaign	Delete or deactivate existing campaign first
`Sole Proprietor campaigns can only have one phone number assigned`	Attempting to assign multiple numbers	Use only one number per SP campaign
`Cannot associate campaign with brand in pending or failed status`	Brand not verified	Complete OTP verification first
`OTP PIN expired`	24-hour verification window exceeded	Trigger a new OTP with `POST /10dlc/brand/{id}/smsOtp`

Retrying OTP

If the OTP expires or the user needs a new PIN, simply call the trigger endpoint again:

curl -X POST https://api.telnyx.com/v2/10dlc/brand/{brand_id}/smsOtp \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -d '{
    "pinSms": "Your new Telnyx verification code is @OTP_PIN@. This code expires in 24 hours.",
    "successSms": "Your Telnyx 10DLC brand has been verified successfully."
  }'

Fees

Item	Amount	Frequency
Brand Registration	$4.00	One-time (charged after verification)
Campaign Vetting	$15.00	Per submission
Monthly Maintenance	$2.00	Monthly

Webhooks

Subscribe to brand and campaign status updates via webhooks. See 10DLC Event Notifications for details on:

10dlc.brand.update — Brand status and identity verification changes
10dlc.campaign.update — Campaign approval/rejection
10dlc.phone_number.update — Phone number assignment status

Next Steps

10DLC Rate Limits

Understand throughput limits for Sole Proprietor campaigns

Event Notifications

Set up webhooks for status updates

Brand API Reference

Full API documentation for brand management

Support Guide

Portal walkthrough for non-API users

Sending Messages

Messaging Profiles

Short Code

RCS

Hosted Numbers

Opt Outs

Phone Numbers

Toll Free Verification

10 DLC

Sole Proprietor 10DLC Registration

Overview

Prerequisites

Registration Flow

Step 1: Create a Sole Proprietor Brand

Response

Step 2: Trigger OTP Verification

Request Parameters

Response

Step 3: Check OTP Status

Response

Delivery Status Values

Step 4: Verify OTP PIN

Step 5: Create a Sole Proprietor Campaign

Response

Step 6: Assign a Phone Number

Error Handling

Common Errors

Retrying OTP

Fees

Webhooks

Next Steps

10DLC Rate Limits

Event Notifications

Brand API Reference

Support Guide

Sending Messages

Messaging Profiles

Short Code

RCS

Hosted Numbers

Opt Outs

Phone Numbers

Toll Free Verification

10 DLC

​Overview

​Prerequisites

​Registration Flow

​Step 1: Create a Sole Proprietor Brand

​Response

​Step 2: Trigger OTP Verification

​Request Parameters

​Response

​Step 3: Check OTP Status

​Response

​Delivery Status Values

​Step 4: Verify OTP PIN

​Step 5: Create a Sole Proprietor Campaign

​Response

​Step 6: Assign a Phone Number

​Error Handling

​Common Errors

​Retrying OTP

​Fees

​Webhooks

​Next Steps

10DLC Rate Limits

Event Notifications

Brand API Reference

Support Guide

Overview

Prerequisites

Registration Flow

Step 1: Create a Sole Proprietor Brand

Response

Step 2: Trigger OTP Verification

Request Parameters

Response

Step 3: Check OTP Status

Response

Delivery Status Values

Step 4: Verify OTP PIN

Step 5: Create a Sole Proprietor Campaign

Response

Step 6: Assign a Phone Number

Error Handling

Common Errors

Retrying OTP

Fees

Webhooks

Next Steps