Everything worth knowing, nothing that isn't.
Why 10DLC exists
US carriers historically tolerated businesses sending from ordinary 10-digit local numbers, but that traffic was unregulated and abused. 10DLC formalised it: to send A2P from a local number in the US you now register your brand and your use case (the 'campaign') with The Campaign Registry, the industry body carriers use to vet senders. Unregistered long-code A2P is increasingly filtered, throttled, or blocked, so registration is effectively mandatory for reliable US delivery.
- Formalises A2P sending from US 10-digit local numbers.
- Requires brand + campaign registration with The Campaign Registry (TCR).
- Backed by the mobile carriers and CTIA industry guidelines.
- Unregistered long-code A2P is filtered or blocked.
How registration and throughput work
You register the brand (the company) and then one or more campaigns (each describing a messaging use case — 2FA, marketing, notifications). Carriers assign a trust score based on the brand's vetting, and that score, together with the campaign type, sets your throughput (messages per second) and daily message caps to each carrier. Better vetting and a legitimate, clearly-described use case raise your limits and improve deliverability; vague or non-compliant campaigns are constrained or rejected.
- Register the brand, then per-use-case campaigns.
- A trust score plus campaign type sets throughput and daily caps.
- Higher vetting raises limits and deliverability.
- Misclassified or non-compliant campaigns are throttled or rejected.
10DLC vs short code vs toll-free — and the MENA picture
10DLC, short codes, and toll-free numbers are the three US A2P paths: short codes are fastest and highest-throughput but costly and slower to provision; toll-free supports A2P after verification; 10DLC is the local-number option for most businesses. Note that 10DLC is a US-specific regime — it does not apply in MENA. In the UAE, Saudi Arabia, Egypt, and neighbouring markets, A2P is authorised through registered alphanumeric sender IDs with the operator or regulator, not through 10DLC.
- Three US A2P options: 10DLC, toll-free, short code.
- 10DLC = local numbers; short code = premium high-throughput; toll-free = verified.
- 10DLC is US-only — it does not apply outside the US.
- MENA uses registered alphanumeric sender IDs instead.
US A2P options compared
| A2P 10DLC | Toll-free SMS | Short code | |
|---|---|---|---|
| Number format | 10-digit local number | Toll-free (8xx) number | 5–6 digit short code |
| Setup | Brand + campaign registration (TCR) | Toll-free verification | Carrier provisioning (weeks) |
| Throughput | Moderate, trust-score based | Moderate | Highest |
| Cost | Low | Low–moderate | High |
| Best for | Most local-number A2P | Higher-volume without a short code | Large-scale, latency-critical A2P |