Sending Speeds
Sending Speeds
Section titled “Sending Speeds”This page shows how fast a Flare SMS campaign sends, so you can plan when a large send finishes. Your speed depends on two things: your Flare plan and the type of number you send from.
How your sending speed is set
Section titled “How your sending speed is set”Every message is limited by two ceilings:
- Your plan speed. Core sends up to 2 messages per second, Pro up to 4, Ultra up to 8, and Enterprise 20 or more (arranged with sales). Your plan speed applies across your whole account, and Flare enforces it.
- The limit for your number type. Carriers set the limit for US 10DLC local numbers and toll-free numbers. SIPSTACK paces each Canadian local number at up to 9 message segments per second.
Your effective speed is the lower of the two. A faster plan does not help when the limit for your number type is lower, and a generous number limit does not raise your plan speed.
All figures are “up to” and are measured on single-segment messages (up to 160 characters, or 70 with special characters or emoji). A longer message is split into segments and each segment counts, so a 2-segment message sends at half the rate. See What slows a send down.
Speeds by plan and number type
Section titled “Speeds by plan and number type”Messages per hour, up to:
| Number type | Core | Pro | Ultra | Enterprise |
|---|---|---|---|---|
| US 10DLC local number ¹ ² | 7,200 | 14,400 | 28,800 | 72,000+ |
| US toll-free | 7,200 | 10,800 | 10,800 | 10,800 |
| Canadian local number ³ | 7,200 | 14,400 | 28,800 | 32,400 |
| Canadian toll-free | 7,200 | 10,800 | 10,800 | 10,800 |
¹ US 10DLC speed depends on your brand’s carrier trust score. These figures assume a vetted brand. Carriers can limit an unscored or low-trust brand to about 4 messages per second (14,400 per hour) or less, whatever your plan. Enhanced (secondary) vetting raises the carrier limit.
² T-Mobile also applies a daily message cap to low-trust brands.
³ SIPSTACK paces each Canadian local number (long code) at up to 9 message segments per second (32,400 per hour), on every plan. On Core, Pro and Ultra your plan speed is lower, so the plan speed applies.
How long 10,000 messages take
Section titled “How long 10,000 messages take”Approximate time to send 10,000 single-segment messages:
| Number type | Core | Pro | Ultra | Enterprise |
|---|---|---|---|---|
| US 10DLC local number ¹ | ~1 h 23 min | ~42 min | ~21 min | ≤ 8 min |
| US toll-free | ~1 h 23 min | ~56 min | ~56 min | ~56 min |
| Canadian local number ³ | ~1 h 23 min | ~42 min | ~21 min | ~19 min |
| Canadian toll-free | ~1 h 23 min | ~56 min | ~56 min | ~56 min |
Footnotes ¹ and ³ are as above. Enterprise speeds start at 20 messages per second, so an Enterprise send from a US 10DLC number can finish sooner.
When you create a campaign, the campaign wizard shows an estimated send time for your audience, based on your plan and sending number.
What slows a send down
Section titled “What slows a send down”- Long or special-character messages. Speeds are metered per segment, not per message. A message longer than 160 characters counts as several segments. A message with emoji or other special characters uses UCS-2 encoding, which fits only 70 characters per segment. A two-segment message sends at half the speed shown above.
- Quiet hours and daily send limits. Sending stops during quiet hours and when you reach your plan’s daily send limit, which stretches the total send time. See SMS Usage, Limits & Billing.
- Carrier trust. An unscored or low-trust US 10DLC brand is limited by carriers, as described in footnote ¹.
How to send faster
Section titled “How to send faster”- Know your Canadian number limits. A Canadian local number sends up to 9 message segments per second, and carriers hold a toll-free number to 3 per second (10,800 per hour). On Core, both are above your plan speed, so they send at the same rate.
- Complete enhanced vetting for US 10DLC. A vetted brand gets a higher carrier limit. Request it from your brand in 10DLC Brands & Campaigns.
- Keep each message to one segment. Stay under 160 characters and avoid emoji to send at the full speed shown.
- Upgrade your plan. If your number type allows more than your plan speed, a higher plan sends faster. See Plans & What’s Included, or contact sales about Enterprise speeds.
For US 10DLC, carrier limits apply to your brand, not to each number, so binding more numbers to your campaign does not raise them.