Throughput here means how many messages per second (MPS) or per day you can send from your 10DLC (10-digit long code) numbers.
It depends on:
The carrier (AT&T or T-Mobile).
The type of use case (marketing, charity, political, emergency, etc.).
Your vetting score (a score given after your brand is checked/verified).
AT&T allows different message speeds depending on use case and vetting score:
High vetted brands (score 75-100) → Up to 4,500 SMS/sec and 2,400 MMS/sec.
Medium vetted brands (50-74) → About 2,400 SMS/sec and 1,200 MMS/sec.
Low vetted brands (1-49) → Only 240 SMS/sec and 150 MMS/sec.
Special cases (like charity, emergency, political, or education) → Different fixed limits:
Charity: 2,400 SMS/sec.
Social apps: 6,000 SMS/sec.
Emergency services: 4,500 SMS/sec.
Sole proprietor (1-person business): Very low, 15 SMS/sec.
Bottom line: Bigger, verified brands = much higher throughput. Small or unverified = very low.
T-Mobile uses a daily cap (instead of messages per second like AT&T):
Top tier brands (75-100 vetting score) → Up to 200,000 messages per day.
High mid (50-74) → 40,000/day.
Low mid (25-49) → 10,000/day.
Low (1-24) → 2,000/day.
Low volume mixed → “Low cap” (around 2,000).
? Bottom line: T-Mobile limits by how many per day, while AT&T limits by messages per second.
Example: 500 users × 100 SMS = 50,000 SMS/day
Even though each user has a small plan, the large number of users adds up.
Total is big (50,000/day), so throughput capacity must be higher than what it looks like per user.
Risk: bursts — if many users send at the same time (like campaigns or alerts).
? Needs mid-to-top tier throughput (T-Mobile High/Mid or AT&T mid-range MPS).
Example: 100 users × 300 SMS = 30,000 SMS/day
Fewer users, so overall daily load is smaller.
Still, each user may send bursts of 300 messages quickly.
Risk: spikes in throughput (MPS requirement) even though daily total is not too high.
? Needs higher per-second speed allowance (AT&T MPS important here).
300 users × 200 SMS = 60,000/day (pretty balanced).
Neither extreme, but still a big daily volume → needs strong throughput.
High Users + Low Plan → Total daily volume is the challenge. Needs higher daily cap (T-Mobile).
Low Users + High Plan → Burst sending is the challenge. Needs higher MPS (AT&T).
Both High (many users × large plan) → Needs top tier on both carriers (200,000/day + 4,500 MPS).
⚡ So, throughput planning is not just about total daily SMS but also about how messages are sent:
Spread across day → daily cap matters.
All at once → per-second speed matters.