A2P 10DLC: the simple guide to US business texting
- A2P 10DLC is a mandatory registration to send business texts from a US local number.
- It's a carrier requirement, not an app quirk: it applies across all providers.
- You register your brand and use cases on your telecom account; the process usually takes a few days.
A2P 10DLC is the registration system that authorizes sending business texts from a 10-digit US local number. "A2P" means application-to-person, "10DLC" refers to the local number. Without this registration, your messages risk being filtered or blocked by carriers.
Good news: it's neither an app's hidden tax nor a trap. It's a rule from US carriers, set up to reduce spam. It applies whatever provider you use.
Why is A2P 10DLC mandatory?
To fight spam and identify who sends what. US carriers require any business sending texts from a local number to register its brand and use cases. In return, your legitimate messages get better deliverability and are filtered less.
A2P 10DLC is a US phone carrier requirement: any business sending texts from a 10-digit local number must register its brand and use cases. This registration happens on the telecom provider account (Twilio, SignalWire, Telnyx) and improves deliverability of legitimate messages.
How do you register, step by step?
In three steps, on your provider account. You register your brand (the company's legal details), declare your campaign(s) (your SMS use cases), then attach your number. The provider forwards to the carriers, who usually approve within a few days.
- Register your brand: legal name, address, business tax ID.
- Declare your campaign: describe what your texts are for (notifications, appointment reminders, client follow-up…).
- Attach your number: link your local number to the approved campaign, and start texting.
With Relay, you do this registration on your provider account, and we guide you step by step. Once approved, you text your clients from the team inbox, at cost and with no trap quota.
Plan ahead: registration usually takes a few days and may carry carrier fees (set by the carriers, not Relay). Anticipate this step if you plan to send US business texts from launch.
What if I only text within Canada?
Rules differ by country and carrier. A2P 10DLC specifically targets US local numbers. For other regions, your provider will tell you the applicable requirements. The principle stays the same: compliance is handled on your telecom account.
A2P 10DLC concerns texts sent from US local numbers. For other countries, requirements vary by carrier and telecom provider. In all cases, SMS compliance is configured on the customer's account, which Relay only orchestrates on the software side.