SMS
SMS is the channel for time-sensitive alerts and promotions that need to be read in minutes. Delivery receipts and opt-out handling are built in.
What you'll need
- Contacts with phone numbers in E.164 format (+countrycode…)
- SMS consent recorded per contact
What you can send
- Alerts: OTP codes, delivery and appointment reminders.
- Promotions: short, time-boxed offers with a clear opt-out.
- Automated steps inside lifecycle flows.
Set it up
- 1
Store numbers in E.164
Phone numbers must include the country code, e.g. +14155550123. The contact import maps a phone column for you.
- 2
Record consent
Only message contacts who opted in to SMS; opt-outs are suppressed automatically.
- 3
Send
Add an SMS step to an automation, create an SMS campaign, or POST /v1/messages with channel "sms".
Delivery & opt-out
Delivery receipts (DLRs) update each message's status. Inbound opt-out keywords add the number to the suppression list so you stay compliant.
Frequently asked questions
What format do phone numbers need?
E.164 — a leading + and the country code, with no spaces or dashes (e.g. +447700900123).
Are unsubscribes handled automatically?
Yes — opt-out replies suppress the number from future SMS sends.
Start sending in minutes
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