Sending speed and capacity

Understand how quickly your SMS can send, which limits apply, and how to plan a batch of any size.

You can launch a batch at one scheduled time. Messages then send at the available rate for your registered campaign and recipients’ networks. Starting a batch at once does not mean every recipient receives it at once.

What determines capacity?

Limit	What it means for your send
Carrier-approved rate	Your registration, campaign type, and vetting determine the permitted rate. AT&T has different rate tiers; 4 texts per second is one tier, not a universal default.
Daily allowance	T-Mobile applies a daily allowance shared across a registered brand’s campaigns. Earlier sends use part of that allowance.
Ready’s effective rate	Ready’s pacing, other traffic, and the sending path can reduce the rate available to your batch. Plan with the effective rate confirmed for your setup.
Recipient delivery	Carrier processing, filtering, and phone availability affect arrival. There isn't a universal instant-delivery guarantee on Verizon, T-Mobile, or AT&T.

Carrier rate reference

AT&T assigns an SMS rate to each registered campaign. These are published tiers, not the rate every Ready account receives.

AT&T campaign tier	SMS per minute	Equivalent per second
Low-volume mixed (T)	75	1.25
Standard (E / F)	240	4
Standard (C / D)	2,400	40
Standard (A / B)	4,500	75

Your actual rate can be lower. These are carrier allowances. Ready's pacing, competing traffic, and your sending setup determine the effective rate available to a batch. T-Mobile's daily allowance is a separate limit; this table doesn't describe Verizon or T-Mobile speeds.

Carrier lanes run in parallel

Ready sends campaign batches through separate carrier lanes. AT&T sends at its assigned rate while T-Mobile and Verizon send alongside it as quickly as available capacity allows. Waiting for an AT&T slot does not make the other lanes wait for that slot.

T-Mobile still has a daily allowance. All lanes share Ready's available processing capacity, and carriers control when a submitted message reaches the phone.

Calculate your sending time

Enter your audience size. The calculator starts with an estimated 30% on AT&T and updates automatically. Change the percentage or enter your actual AT&T recipient count when known. Use 100% for a cautious AT&T planning estimate.

Total recipients Estimated AT&T share (%)30% is a planning assumption, not your audience’s measured carrier mix. AT&T recipients AT&T sending rate per second4 is the standard E / F carrier allowance. Use your effective rate if known.

Estimated AT&T sending time2 min 30 sec

1,400 recipients use the other carrier lanes.

One-segment SMS only. This calculator uses your inputs, not your account data. It assumes a constant rate, no competing traffic, an approved campaign, and sufficient credits and daily allowance. It estimates the AT&T lane, not the full batch or recipient arrival time.

Only count the AT&T portion against the AT&T rate. With 2,000 recipients, including 500 on AT&T, that lane takes about 2 minutes 5 seconds at 4 per second. The other 1,500 send through their own lanes alongside it. Their completion time depends on available capacity and allowances.

Long messages can use multiple SMS segments. For these, confirm how segment count affects your effective sending rate before using this estimate. Leave a buffer for carrier delivery when planning a deadline.

Read account limits through the API

Your integration can call GET /v1/registration/throughput with a Ready API key to read the account's T-Mobile daily allowance, usage reliability, warm-up limits, and recent sending activity. Responses can be cached for up to one minute.

To read a particular brand's carrier assignments, call GET /v1/registration/{brand_id}/limits. It returns AT&T rates per campaign, T-Mobile's shared brand allowance, and Verizon's reported rate when available. No recipient validation is needed. These are assigned allowances, not measured sending speeds; don't use recent message volume as a substitute for the permitted burst rate.

Other sending limits

Registration: pending or unapproved campaigns can have restricted sending. Confirm approval before planning a large send.
Shared capacity: concurrent workflows and numbers under the same registration can share allowances. Adding numbers does not automatically multiply capacity.
Message length: long messages and certain characters can create multiple billable SMS segments. MMS has different throughput and pricing.
Sending eligibility: unsubscribed contacts, suppression checks, configured sending windows, and available credits can affect which messages send and when.
Delivery status: submitted, queued, and delivered are different states. A batch accepted for sending isn't confirmation that everyone received it.
Daily exhaustion: traffic can be delayed or rejected when an allowance is exhausted. A delayed message may miss the time you intended it to arrive.

Can capacity be increased?

Ready can review your approved use case and registration for available capacity options, including brand vetting where appropriate. An upgrade depends on approval and is not guaranteed. Do not assume extra brands or sending numbers bypass existing limits.

Need help with an unusual setup or a capacity increase? Email support@tryready.com when planning a large or time-sensitive send.