2FA codes & OTPs
OTP delivery over SMS is sensitive to timing and number consistency. Shared carrier pools mean codes can arrive from numbers users do not recognise, which increases abandonment. A dedicated SIM with a single, consistent number avoids this.
When a user requests a verification code, your system sends an outbound message request. Relayion dispatches it to the paired device. The SIM sends it. The user receives the code from a number they've seen before, not a rotating short code from a shared pool.
For applications where delivery speed matters, Relayion supports multi-SIM targeting. If you have a second device as a backup, you can target a specific SIM slot or a different device entirely. Your retry logic decides when to fall back and the API supports it either way.
Authentication codes are time-sensitive. Relayion provides webhook events for dispatch, delivery, and failure so your system knows whether the code reached the user or whether a retry is warranted, without polling.
One device, one SIM, one number. No shared infrastructure between your users and anyone else's.
Carrier compatibility varies by market. Check coverage →
Clinic appointment reminders
Send reminders from the clinic's own number. Patients already have it saved. Replies route back to your system.
Read →AIAI agents that text humans
Give your AI agent a real phone number. Outbound messages and inbound replies flow through the same API.
Read →E-commerceOrder & shipping updates
Confirmations and dispatch notifications from a number your customers recognise. Flat monthly cost.
Read →Ready to connect your first device?
Free plan. One device, 500 messages per month. No credit card required.