10DLC Throughput Limits by Carrier (AT&T, T-Mobile, Verizon)

10DLC throughput is where carrier diversity bites: each major US carrier limits registered traffic on a different axis. If you plan a send assuming one number, you can watch messages queue for hours (or fail) on another. Here is the mental model, current as of 2026 (exact numbers shift; treat your provider’s dashboard as the source of truth).

Three carriers, three models

AT&T: messages per minute, per campaign

AT&T assigns each campaign a class based on the brand’s trust score and use case. Each class carries a messages-per-minute (MPM) rate, from tens of MPM for unvetted brands to thousands for top classes. The limit is a rate: you can send all day, but never faster than your class allows.

T-Mobile: message segments per day, per brand

T-Mobile caps daily volume: message segments per calendar day across all of a brand’s campaigns combined. Tiers run from roughly 2,000 segments/day for unvetted or low-scored brands, through intermediate tiers (10,000 / 40,000 / 200,000), up to unlimited for top scores. Two things surprise people: the cap is brand-wide (ten campaigns share one bucket), and it counts segments, not messages, so a 300-character message consumes two or more segments.

Verizon

Verizon does not publish score-based tiers the way AT&T and T-Mobile do; it applies its own traffic management and filtering. In practice Verizon is rarely the throughput bottleneck for registered traffic, but it filters content aggressively, so deliverability there is earned by list hygiene rather than vetting scores.

What this means for real campaigns

• Know your segment math. GSM-7 encoding fits 160 characters in one segment (153 when concatenated); a single emoji switches the message to UCS-2 and halves that. Long marketing messages routinely cost 3–4 segments against your T-Mobile daily cap.
• Spread time-critical sends. If your AT&T class allows 240 MPM and you queue 50,000 messages at 9:00 AM, the tail lands hours later. Schedule in waves or upgrade your class via secondary vetting.
• Watch the brand-wide bucket. On T-Mobile, a marketing blast from one campaign can starve your OTP campaign the same day. High-priority transactional traffic deserves headroom planning.
• Queued is not failed. Providers like Twilio queue over-limit traffic and drain it as capacity allows. If messages seem slow rather than missing, check throughput before debugging deliverability.

Raising your limits

1. Secondary vetting is the main lever. A ~$40 vet that lifts your score can multiply both AT&T MPM and T-Mobile daily caps. See how vetting works.
2. Right-size your use case, since some special use cases (e.g. 2FA at scale) receive favorable treatment.
3. Move volume off 10DLC. If you genuinely need six-figure blasts in minutes, that is short code territory.

Throughput planning is unglamorous, but it is the difference between "the flash sale SMS landed at 9:02" and "customers got it after the sale ended." Know your class, know your caps, and count your segments.

Frequently asked questions

What is a message segment?

The billing and throughput unit of SMS. GSM-7 encoded messages hold 160 characters per segment (153 when a message spans multiple segments); messages containing non-GSM characters like most emoji use UCS-2 encoding at 70/67 characters per segment. Carriers count segments, not messages.

Do throughput limits apply to toll-free and short codes?

Not the 10DLC tiers. Toll-free has its own (generally generous) throughput, and short codes offer the highest rates, typically hundreds of messages per second. The tier system described here is specific to 10DLC.

What happens when I exceed my limit?

Your provider typically queues excess messages and releases them as capacity frees up (Twilio does this per carrier). Severely over-limit traffic on T-Mobile’s daily cap can fail outright once the daily bucket is exhausted.