🛡️ CloudTalk is built for scalable, secure business communication — but due to how third-party OTP systems work, we cannot guarantee that OTP or Two-Factor Authentication (2FA) codes sent from other companies will be delivered to CloudTalk phone numbers.
This article explains why and what you can do instead.
🔍 Why is this a limitation?
CloudTalk provides VoIP (Voice over Internet Protocol) phone numbers — these are virtual numbers, not tied to a SIM card or mobile carrier.
Most platforms that send OTPs (like banks, social media, and software tools) have strict delivery policies and often block or deprioritize delivery to VoIP numbers.
Here’s why:
OTP senders often whitelist only mobile carrier numbers. VoIP numbers are typically excluded.
SMS aggregators and routing systems may block virtual numbers due to anti-fraud policies.
Some services silently filter or drop messages when the number doesn’t meet their criteria.
This means OTP and 2FA codes sent from other companies may not reach your CloudTalk number — even if SMS is working normally otherwise.
✅ What is supported?
You can absolutely send outbound automated messages using your CloudTalk numbers as part of your own business workflows.
However, receiving verification codes from third-party services (Amazon, banks, etc.) is not guaranteed.
Use Case | Supported? |
Sending outbound OTPs via CloudTalk SMS | ✅ Yes |
Receiving marketing or customer messages | ✅ Yes |
Receiving OTPs/2FA from third-party apps | ⚠️ Not guaranteed |
Using CloudTalk number for secure logins | ⚠️ Not recommended |
💡 Best alternatives
For services that require verification codes, we recommend:
Using a mobile number from a mobile carrier instead of a VoIP number.
Setting up an authenticator app (e.g. Google Authenticator, Authy, or Microsoft Authenticator).