Informational SMS and One-time PIN (OTP/2FA)

Our priority-zero routes let us deliver informational SMS and OTP/2FA messages safely within seconds.

OTP verification service

Priority delivery for informational SMS

Send critical SMS (OTP codes, 2FA, transactional notifications) safely within seconds with Calisero.

  • Payment deadline SMS notifications
  • Order status SMS notifications
  • Courier / parcel delivery SMS notifications
  • OTP and 2FA codes sent via SMS
  • Alerts and important notification SMS
  • Appointment confirmations and SMS reminders
Learn more
Transactional SMS service

Send One-time PIN (OTP/2FA) SMS in seconds

Verify user identity, secure account access, and validate sensitive actions.

  • 6-character OTP code managed by Calisero
  • Built-in anti-fraud mechanisms
  • Advanced reporting
  • Monitoring for every validation attempt
  • Option to customize messages
  • "Verify" sender included
Learn more
Send test SMS for free

Try Calisero for free, with no obligation.

Try it for free — you have €1 credit!

Create an account now and get €1 credit to try Calisero — sufficient for 28 test SMS.
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