01
Your app requests a code
Your backend generates a short-lived OTP and calls the Boxis API with the user destination.
OTP Services
One-time passwords via SMS and voice — API-ready, Swiss telecom
Secure logins, payments and high-risk actions with short-lived codes delivered by SMS OTP (Boxis SMS Pro) or Voice OTP (automated call speaking the code).
- SMS + Voice channels
- API-ready integration
- Swiss telecom partner
Delivery speedCodes delivered in seconds for time-sensitive auth flows.
Dual-channel fallbackRetry via Voice OTP when SMS is delayed or unavailable.
Audit trailLog send attempts, statuses and channel used for each OTP.
Global reachStrong coverage in Switzerland plus international SMS where applicable.
Delivery channels
SMS OTP and Voice OTP
Choose the channel that fits your risk profile — or combine both with fallback.
SMS OTP
Deliver one-time codes via Boxis SMS Pro / business SMS — ideal for login MFA, password reset and payment confirmations.
- Fast mobile delivery
- Sender ID options
- API & webhook ready
- CH + international SMS where available
Voice OTP
An automated phone call speaks the code aloud — useful when SMS is blocked, for landlines, or as a secondary channel.
- Spoken code playback
- Works on mobiles & landlines
- Fallback after SMS retry
- Telephony-grade reliability
How it works
Three steps to deliver an OTP
02
We deliver SMS or Voice
The code is sent by SMS, or spoken on a Voice OTP call — with optional fallback between channels.
03
You verify & log
The user enters the code; you validate it and keep an audit trail of channel and status.
Use cases
Where OTP protects critical actions
Login MFA
Second factor at sign-in for portals, banking and employee apps.
Payment confirm
Confirm transfers and checkout steps with a short-lived code.
Password reset
Prove phone ownership before allowing credential recovery.
High-risk actions
Step-up verification for IBAN changes, admin grants or data export.
Tech & security
Controls that keep OTP usable and safe
Rate limits, short-lived codes and channel fallback reduce fraud without blocking legitimate users.
Rate limitsThrottle OTP requests per user and destination to limit abuse.
Sender IDBrand-aligned SMS sender identity where operators allow it.
Short-lived codesCodes expire quickly so intercepted messages lose value.
SMS → Voice fallbackRetry or switch to Voice OTP when SMS delivery fails.
Delivery loggingStatus callbacks and logs for ops, support and compliance reviews.
Swiss hostingPlatform and support from Boxis in Switzerland.
When to use which
SMS OTP vs Voice OTP
Prefer SMS OTP when
Users expect a text, you need high throughput, and mobile coverage is strong. Best default for login MFA and resets.
Prefer Voice OTP when
SMS is filtered, users are on landlines, or you need a clear fallback after failed SMS delivery for high-risk steps.
FAQ
OTP Services questions
What is an OTP?
A one-time password: a short code valid for a limited time, used to prove that the user controls a phone number during authentication or sensitive actions.
SMS OTP vs Voice OTP — which should I use?
Start with SMS for most flows. Add Voice OTP as fallback or for users who cannot receive SMS reliably.
How do I integrate OTP?
Via API: your application requests delivery, Boxis sends SMS or places a Voice OTP call, then you verify the code on your side.
Is pricing public?
OTP and SMS volumes vary by destination and channel. Contact sales for a quote based on your countries and monthly volume.
Where is the service hosted?
Boxis operates as a Swiss telecom provider; platform components and support are based in Switzerland.
Can I use both channels together?
Yes. Many deployments send SMS first and fall back to Voice OTP on failure or after a timeout.
Does this replace MFA apps?
OTP by SMS/Voice is one MFA method. You can combine it with authenticator apps or passkeys depending on your security policy.