Messages per second (MPS) is the rate at which a business can send text messages through a given number, campaign or account before carriers or the messaging provider start queuing or limiting traffic. Throughput limits exist at several layers, set by the sender type, the business’s registration, the carriers receiving the messages and the provider’s own platform. For most buyers, MPS is what decides whether a one-time passcode arrives in seconds or minutes, and whether a 100,000-message campaign finishes in minutes or hours.
At a glance
- MPS is a sending rate; it sets how quickly messages leave your platform toward the carriers, not whether they’re delivered.
- Limits come from several places: sender type, registration and vetting, individual carriers and the provider’s platform.
- As a general pattern in the US, short codes allow the highest throughput, with verified toll-free and registered 10DLC numbers varying by registration; exact limits change.
- Long messages are often counted per segment, so throughput in messages can be lower than the headline figure.
- Traffic over the limit is usually queued, adding delay, though persistent overruns can be rejected or filtered.
What problem it solves
Carriers need to protect their networks and subscribers from floods of unwanted texts. Without limits, a single sender could push large volumes of spam before anyone noticed. Throughput limits let carriers give well-identified senders more capacity and keep unknown or risky senders slow.
For a business, understanding MPS solves a planning problem. If you know your limits you can size campaigns, keep one-time passcodes and alerts from getting stuck behind bulk traffic, and pick the sender type that fits your peak volume.
How it works
Per-sender limits. In the US, 10DLC limits generally depend on the registered brand’s vetting results and campaign type, as recorded with The Campaign Registry, and different carriers may apply them in different ways. Verified toll-free numbers have their own limits, which depend on toll-free verification and the provider. Short codes are typically provisioned for high throughput. Some limits are set per carrier, so overall throughput may not be one simple number.
Volume caps. Some carriers or providers also apply daily or other volume caps, such as a cap per registered brand, separate from the per-second rate.
Segments. An SMS has a maximum length per segment; longer messages are split and reassembled on the phone. Many providers count each segment against throughput and billing. Characters outside the standard SMS character set, such as many emoji, can reduce how much text fits in each segment.
Provider queuing. Most messaging platforms accept messages from your application faster than they can send them, hold the excess in a queue and release it at the allowed rate. Some let you prioritize urgent traffic, such as passcodes, ahead of bulk sends.
What it doesn’t cover. A high MPS doesn’t make messages deliverable. Content, complaints and mismatched use cases can still trigger carrier message filtering.
Our CPaaS solutions page covers how to compare providers on throughput, queuing and reporting.
When it matters for buyers
- Passcodes and alerts arrive late at busy times, often because they share a queue with bulk sends.
- Planning a campaign or emergency notification that has to reach a large list within a set time.
- Choosing a sender type, where throughput is one of the main differences between 10DLC, toll-free and short codes.
- Growing volume, when limits set at registration no longer fit actual traffic.
Questions to ask vendors
- What throughput and any daily caps will apply to our numbers and campaigns today, per carrier?
- Do you count throughput per message or per segment?
- How do you queue traffic over the limit, and can we prioritize time-sensitive messages?
- How can we raise our limits, and what does that cost and how long does it take?
- Do you report queue time separately from carrier delivery time?
- Would a different sender type better fit our peak volumes?
How it differs from carrier message filtering
Both can make texts arrive late or not at all, but for different reasons. MPS is a rate limit: messages wait in a queue and go out at the allowed pace, so the usual symptom is delay. Carrier message filtering is a judgment about the traffic itself: messages a carrier decides are unwanted or suspicious may be blocked, and the usual symptom is non-delivery. Raising throughput won’t fix filtering, and fixing content won’t raise throughput, so diagnose which one you’re dealing with first.