When a customer is creating an account, signing in, resetting a password, or confirming an important action, the message they receive isn't marketing — it's part of the product experience. A verification code that arrives too late can stop a registration. A delayed authentication message can prevent a customer from completing an important action.
Emisri enables businesses to send transactional SMS for OTPs, authentication and verification workflows, connecting messaging to the events and journeys that drive the customer experience.
Where it's used
Account registration, phone number verification, login verification, two-factor authentication, password resets, transaction confirmation, new-device verification, and security notifications. The message is usually simple — the workflow behind it can be much more sophisticated.
A typical OTP workflow
Customer requests verification → System generates OTP → Emisri sends SMS
↓
Customer receives & enters code → System validates OTP → Verified
The key point: the SMS is triggered by an actual customer action. This is transactional communication, not a campaign broadcast.
Keep the message focused
An OTP message should make the required action obvious — nothing marketing-style, nothing to interpret:
"Your ABCFood verification code is 482913. It expires shortly. If you did not request this code, please ignore this message."
OTP is one part of a bigger picture
Authentication workflows cover several distinct events, each with its own message: account verification, login verification (new device), password reset, transaction verification, and security alerts. Each event deserves its own message and workflow — not a one-size-fits-all template.
Design for things going wrong
Customers will request a code twice, enter the wrong one, let it expire, lose connectivity, or abandon the process halfway. These aren't edge cases — they're normal, and should be part of the workflow design from the start.
Repeated requests: if every request generates a new independent OTP, customers get confused about which code is valid. A better pattern: generating a new code invalidates the previous one.
OTP requested → Send code → Customer requests another?
NO → Wait
YES → Generate new code → Previous code invalid → Send SMS
Expired codes: should have a defined validity window and require a fresh request once expired — the SMS can simply note "it expires shortly" without over-explaining.
Incorrect attempts: the app should handle valid / invalid / expired / too-many-attempts as distinct states, each triggering a different next step.
Password reset follows the same logic
Password reset requested → Verify customer → Generate OTP → Send SMS
↓
Customer enters code → Verification successful?
YES → Continue reset
NO → Retry / expire
A short SMS, but it enables a critical customer journey.
New-device sign-in and transaction verification
For unrecognized devices: "Your verification code is 582104. Enter it to complete sign-in." For sensitive actions (account changes, high-risk transactions), the message should clearly state what's being verified — treat these differently from marketing since the customer expects immediate action.
OTPs vs. security alerts — not the same thing
An OTP asks the customer to do something. A security alert informs them something happened:
"A new sign-in was detected on your account. If this wasn't you, review your account security."
Don't treat every security message as an OTP — different purposes need different messaging.
Channels working together
SMS can pair with Email for a layered experience — e.g., SMS for the immediate alert, Email for fuller account/security guidance. Voice can serve as a fallback for certain verification journeys where SMS alone isn't sufficient — but any fallback should be intentional, not just the same OTP blasted through every channel.
It's event-driven by nature
Account created → verification SMS. Login needs verification → OTP. Password reset requested → authentication message. Sensitive action initiated → confirmation code. The application creates the event; the messaging workflow responds.
This isn't a marketing campaign
Authentication messages should be triggered by a specific event, clear, time-sensitive, focused on the required action, and separated from promotional content. The customer requested the action — the message exists to help them complete it securely.
Edge cases worth planning for
OTP not received → retry mechanism, without uncontrolled repeated sends
Multiple requests → define which code stays valid
Too many incorrect attempts → trigger the appropriate security response
User abandons verification → let the journey expire cleanly
Suspicious activity → trigger the appropriate security workflow
These rules belong to the authentication system; messaging supports the communication layer.
Monitor what matters
Useful metrics: delivery performance and latency, verification completion vs. failure, expired OTPs, retry requests, and abandonment. If many customers request a second OTP shortly after the first, that's a signal to investigate the experience or delivery performance.
Part of a larger journey
Registration → Verification SMS → OTP validated → Account activated
→ Welcome journey → Product onboarding
Verification stays transactional and focused; once it's done, the customer moves into a separate onboarding experience.
Where AI fits
AI can help map authentication journeys, identify edge cases, generate concise message variations, and analyse verification performance for unusual patterns — but it doesn't replace the underlying authentication system. That system generating, validating and expiring the OTP remains the source of truth; AI supports the communication layer around it.
Where Emisri fits
Your application → Authentication event → Messaging workflow → Emisri → SMS → Customer
The application decides an authentication message needs to go out; Emisri handles the messaging workflow; the customer receives the SMS and continues in the application. This makes Emisri useful not just for marketing, but for the transactional messages that keep digital products functioning.
The six digits that matters
The SMS may contain only six digits, but the journey behind it — creating an account, signing in, recovering access, confirming a transaction — can be critical. Authentication communication deserves to be treated as part of the product experience, not another marketing message.
Trigger the right message. Deliver it when it matters. Let the customer complete the action securely.