10DLC (10-Digit Long Code) is a US regulatory framework for A2P SMS messaging sent via standard 10-digit phone numbers. Prior to 10DLC, businesses used standard long codes for A2P traffic without carrier registration, resulting in high spam filtering rates. Under 10DLC, businesses must register their brand and messaging campaigns with The Campaign Registry (TCR), which shares this information with US carriers (AT&T, T-Mobile, Verizon). Registered 10DLC campaigns benefit from higher throughput, lower filtering rates, and better deliverability than unregistered traffic.
10DLC (10-Digit Long Code) is the US carrier framework for registering A2P SMS traffic sent from standard 10-digit phone numbers. It was introduced because unregistered A2P traffic on long codes was being heavily filtered by carriers as spam. By registering with The Campaign Registry (TCR), businesses prove to carriers that their messaging is legitimate, their brand is verified, and their use case is compliant. In return, registered campaigns receive better throughput, far lower filtering rates, and improved message deliverability. Unregistered A2P traffic on US long codes faces significant filtering and is effectively unusable for business messaging.
10DLC registration is a two-step process: brand registration and campaign registration. For brand registration, you submit your business details to The Campaign Registry (TCR) — legal business name, EIN (Employer Identification Number), industry vertical, and contact information. Your brand is then assigned a Trust Score based on third-party data. For campaign registration, you describe each specific messaging use case (e.g. ‘two-factor authentication’ or ‘customer care’), provide message samples, and specify which numbers will send that campaign. Your messaging provider (such as IDT Express) submits registration on your behalf or provides a portal for self-service registration.
The Campaign Registry (TCR) is the central hub for US A2P 10DLC registration, established by the major US mobile carriers (AT&T, T-Mobile, Verizon) to combat SMS spam. All businesses wishing to send A2P SMS via 10-digit long codes in the US must register their brand and campaigns through TCR. TCR verifies business identity, assigns Trust Scores, and shares campaign data with carriers to allow them to provision appropriate throughput and filtering thresholds. TCR charges a one-time brand registration fee and an ongoing monthly campaign fee.
Unregistered A2P SMS traffic on US long codes is subject to aggressive carrier filtering — messages may be blocked entirely, delayed, or delivered at severely throttled rates (as low as 1 message per second). Since 2023, US carriers have actively blocked unregistered A2P traffic on long codes, meaning unregistered senders experience near-zero deliverability for business messaging. Beyond filtering, sending unregistered A2P traffic violates carrier terms of service and can result in account suspension. Registration is effectively mandatory for any business sending commercial SMS in the US.
