Reference
Should I be using a short code or a long code (A2P 10DLC) to send SMS in the USA?
Key points
- If you plan to send more than a few hundred messages per day, or need to send large bursts of messages quickly, a short code is strongly recommended.
- If your use case is conversational, support, or low-volume notifications, a long code (A2P 10DLC) is usually sufficient.
- For marketing, promotions, or any high-volume application, short codes are the carrier-preferred method and will ensure your messages are delivered reliably and quickly.
Feature comparison
| Feature | Short Code | Long Code (A2P 10DLC) |
|---|---|---|
| Best for | High-volume, time-sensitive messaging (e.g., marketing, alerts, 2FA). | Lower-volume, conversational, or transactional messaging. |
| Volume / throughput | Up to 100 messages per second (MPS) by default. | Typically 1 MPS per long code; higher throughput possible with proper registration and pooling (up to 75 MPS). |
| Filtering | Minimal carrier filtering; ideal for promotional or high-risk content. | More likely to be filtered for high-volume or promotional content. |
| Use Cases | Marketing campaigns, large notification bursts, transactional notifications (e.g. 2FA) | Customer support, appointment reminders. |
| Cost | Higher setup and monthly fees. See table on cost breakdown below. | Lower setup and monthly fees. See table on cost breakdown below. |
| Provision and registration | Short codes are provisioned for specific use cases and must be approved by carriers | Use-case registration required |
| Approval time | 8–12 weeks | Few days |
| Geography | Can only message US recipients | Can message US and international recipients |
Cost comparison: Short code vs Long code (A2P 10DLC)
| Cost Type | Short Code | Long Code (A2P 10DLC) |
|---|---|---|
| Setup fee | $1,000–$1,500 (one-time) | $0 (registration: $4–$44) |
| Monthly fee | $500–$1,000 | $1–$2 per number |
| Per message SMS | Same | Same |
| Approval time | 8–12 weeks | Few days |
What does A2P 10DLC mean?
A2P 10DLC stands for Application-to-Person 10-Digit Long Code. It is a messaging system in the United States that allows businesses to send SMS and MMS messages to consumers using standard 10-digit phone numbers (long codes), but with special registration and compliance requirements.
Why it exists: U.S. mobile carriers introduced A2P 10DLC to improve message deliverability, reduce spam, and allow higher messaging throughput for legitimate business use cases.
Registration required: Businesses must register their brand and messaging campaigns with The Campaign Registry (TCR) before sending A2P messages over 10DLC numbers. This includes providing details about your business, use case, and sample messages.
Short code feature support
2-way SMS: US short codes can both send and receive SMS messages with US mobile numbers on supported carrier networks.
Carrier support: While most major and many minor US carriers support short codes, there are a few smaller carriers and services (like Google Voice) that may not support short code messaging.