What Is 10DLC and Why It Is Required?
What Is 10DLC?
10DLC (10-Digit Long Code) refers to standard local phone numbers that businesses use to send A2P (Application-to-Person) SMS and MMS messages. It is designed for businesses that send automated or high-volume text messages such as notifications, alerts, confirmations, reminders, and two-factor authentication codes.
Mobile carriers no longer allow A2P messaging through unregistered local numbers. To continue sending business text messages reliably, companies must register their Brand and Campaign through The Campaign Registry (TCR) — the messaging authority approved by U.S. carriers.
Why 10DLC Exists
10DLC was created by U.S. mobile carriers in response to:
- Growing SMS spam and fraud
- Abuse of P2P routes for automated business messaging
- The need for transparency about who is sending messages and why
Carriers now require 10DLC registration so they can accurately verify message origin, enforce throughput limits, and protect mobile subscribers from unwanted or deceptive messages.
Important Note
10DLC is not a requirement created by Flagman Telecom. It is an industry-wide compliance requirement enforced by:
- U.S. mobile carriers (AT&T, T-Mobile, Verizon, etc.)
- Messaging ecosystem organizations (The Campaign Registry, CTIA)
- Federal regulators overseeing consumer protection (FCC, FTC)
All service providers — including hosted PBX platforms, VoIP carriers, SMS aggregators, and CPaaS platforms — must comply with these same rules.
Why 10DLC Registration Is Required
Businesses must register for 10DLC because unregistered A2P traffic is subject to:
- Carrier blocking or filtering
- Higher surcharge fees
- Reduced throughput (very slow message delivery)
- Full traffic suspension in repeated non-compliance cases
Registration ensures:
- Higher message deliverability
- Fewer blocks and spam flags
- Compliance with U.S. messaging regulations
- Clear identification of the sender and campaign purpose
Official FCC & Industry References
Below are the primary official sources explaining why messaging verification frameworks like 10DLC exist and how carriers are allowed to filter, block, or verify messages:
FCC – Consumer Protection Rules
- FCC – Consumer Guide: Stop Unwanted Robocalls and Texts
- Federal Register – Unlawful Text Messages (TCPA Rulemaking)
- FCC – Rules Focused on Scam Texting
- FCC – Combating Scam Robocalls & Robotexts
- FCC – Unwanted Calls/Texts Complaints
CTIA Messaging Guidelines
The Campaign Registry (TCR)
Why This Matters for Your Business
If your business sends text messages from a local phone number — including:
- Two-factor authentication codes
- Appointment reminders
- Notifications and alerts
- Customer service texts
- Order updates
- Marketing messages
- Missed call or voicemail SMS alerts
— then 10DLC registration is required by all major U.S. mobile carriers.
Failure to register typically results in:
- Messages being marked as spam
- Messages being blocked completely
- Higher per-message fees
- Possible suspension of all SMS traffic
Summary
- 10DLC is a national messaging compliance standard.
- It is required by U.S. mobile carriers, not by individual VoIP providers.
- The FCC authorizes carriers to filter and block unverified traffic.
- CTIA guidelines shape how the ecosystem verifies business messaging.
- Registration improves message delivery rates and protects consumers.
