Are JoltSMS Numbers VoIP?
Short answer: Many numbers available for rent are VoIP (virtual) SMS-capable numbers. In some regions we may also provide mobile-class numbers. Availability varies and no provider can guarantee acceptance by every app or service.
What "VoIP" vs "Mobile" Means
VoIP numbers
- Provisioned via virtual carriers.
- Typically SMS-only in our context (no voice), private to your account.
- Some apps/services detect and may restrict VoIP numbers for onboarding or 2FA.
Mobile numbers
- Hosted by mobile operators (or treated as such).
- Often better acceptance with certain services, but still not guaranteed.
- Each service applies its own checks and risk rules.
Acceptance of a number (VoIP or mobile) is ultimately controlled by the destination app/service, not JoltSMS.
Why Some Services Reject VoIP
Many large platforms try to reduce abuse by filtering on number type and reputation. Even mobile numbers can be blocked if their reputation or usage pattern triggers risk rules. Common factors include:
- Known "public" or overused ranges
- Velocity/repeat sign-ups
- Geography & IP/proxy mismatches
- Browser/device fingerprint anomalies
See Number Cannot Be Used for mitigation tips.
How to Choose the Right Number
Check your target app's policy
If they're known to block VoIP, prefer a mobile-class number (when available).
Test on a small scale first
Use our Inbox to verify receipt before automating.
Align signals
Match IP/region, use a clean browser profile, and avoid repetitive patterns.
Does JoltSMS Show the Number Type?
Where available, we surface carrier metadata (e.g., operator/country). Number type/class can be inferred in some regions, but may not be shown uniformly. If type is critical for your workflow, contact support with your target app(s) and region requirements.
Will a VoIP Number Work for OTP?
Often yes—but not everywhere. Many services deliver OTPs to VoIP; others do not. The safest approach is:
- Start with a quick live test (send OTP, confirm in Inbox).
- If blocked, try a different region/route or a mobile-class option if offered.
Voice & Call-Back Codes
Unless explicitly stated, our numbers are SMS-only. Services that require voice call-back verification won't work. If you need voice, contact support about availability.
API & Integrations Still Work the Same
Regardless of number type, you get:
- Private Inbox (searchable, retained per your plan)
- Slack/Discord/Email notifications
- Webhooks for automation
See Receive OTPs & Codes to wire up notifications.
FAQ
Q: Can you guarantee a non-VoIP (mobile) number for a specific app?
A: We can't guarantee acceptance by a third party. We recommend testing and following our verification checklist.
Q: My number worked last week and now it's blocked—why?
A: Apps regularly update filters. Review your IP/region, browser hygiene, and action velocity. Try another route/region.
Q: Do you recycle numbers?
A: Numbers are rented privately to you during your term. We manage reputation and rotation to maintain deliverability.