Non-VoIP
[nɒn vɔɪp]A non-VoIP number is a mobile or landline number not linked to a VoIP (Voice over IP) service. These numbers are provided directly by traditional telecom carriers and are commonly used for voice calls, SMS, and secure verifications.
Why non-VoIP matters
Non-VoIP numbers play an important role in messaging reliability, compliance, and trust - especially in industries like finance, healthcare, and education. Carriers and apps often prefer non-VoIP numbers for sending verification codes (OTP), alerts, or sensitive data due to their association with real identities and physical devices.
Businesses may use non-VoIP numbers to avoid carrier filtering or to support use cases where regulations require traditional telecom infrastructure. They’re also preferred for SMS-based authentication in many apps and platforms.
Clerk Chat supports both VoIP and non-VoIP messaging, allowing businesses to choose the setup that fits their compliance, scale, and operational needs.
How non-VoIP works
Here’s how non-VoIP numbers function in a messaging context:
- Issued by mobile carriers – These numbers are assigned by wireless carriers or landline providers, not VoIP platforms.
- SMS/MMS support – Non-VoIP mobile numbers support native SMS and MMS out of the box.
- Text-enablement for landlines – Landlines can be text-enabled using a messaging provider like Clerk Chat.
- Carrier identification – Non-VoIP numbers are easier to identify and authenticate for services like OTP delivery.
- Platform integration – Businesses can connect these numbers to Clerk Chat to enable two-way messaging and automation.
- Compliance support – Because they’re tied to verified identities, they’re often used in high-compliance messaging scenarios.
Whether you’re texting customers or verifying accounts, non-VoIP numbers can improve deliverability and trust.
Best practices with non-VoIP
Use for authentication - Non-VoIP numbers are widely accepted for two-factor and account verification messages.
Text-enable landlines - Bring your business number into Clerk Chat without affecting phone service.
Check carrier compatibility - Verify that your number supports SMS/MMS before using it for campaigns.
Avoid using personal numbers - Use business-issued non-VoIP numbers for professional, trackable messaging.
Use platforms with compliance support - Clerk Chat helps manage opt-ins, delivery monitoring, and routing.
Don’t rely on non-VoIP alone - Consider combining non-VoIP and VoIP numbers depending on your use cases.
Secure your accounts - Whether VoIP or not, always use multi-factor authentication and audit access logs.
Real world examples
- Finance
Used non-VoIP numbers for secure OTP delivery during client onboarding.
Read more - Healthcare
Chose non-VoIP texting for HIPAA-compliant appointment reminders.
Read more
Common misconceptions
Mobile numbers from wireless carriers are typically non-VoIP unless ported to a VoIP service.
They can - many platforms, including Clerk Chat, can enable SMS on mobile and landline numbers.
VoIP numbers offer flexibility, while non-VoIP numbers are ideal for verification or regulatory use.
Platforms like Clerk Chat support both VoIP and non-VoIP numbers, depending on your setup and goals.
Related terms
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FAQ
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Find what you need quickly and clearly with our most frequently asked questions.
A non-VoIP number is a phone number not associated with Voice over IP services. These include traditional mobile numbers issued by carriers like AT&T or Verizon, and landlines not tied to internet calling apps.
Non-VoIP numbers are often preferred for sensitive use cases like account verification, compliance-heavy industries, or message deliverability because they’re seen as more trustworthy by carriers.
Yes. Both SMS and MMS are supported on most non-VoIP mobile numbers, and many landline numbers can be text-enabled using platforms like Clerk Chat.
You can use number lookup tools or contact your provider. Clerk Chat can also verify carrier type when setting up messaging on a number.
They're often preferred for verification purposes, but both VoIP and non-VoIP numbers can be secured with proper authentication, encryption, and compliance practices.
Yes. Clerk Chat works with both non-VoIP and VoIP numbers, including mobile carriers, landlines, and toll-free lines - helping you stay compliant and connected.
