You may notice that some SMS messages sent from outside the USA do not arrive. This is because Skype numbers—along with many other US-based VoIP numbers—do not natively support receiving international SMS. Delivery of such messages is not guaranteed and works on a best-effort basis.
However, SMS sent from US numbers to your US Skype number should be received without any issues. If your bank, app, or service provider previously registered your Skype number for two-factor authentication, you should continue to receive OTP messages as normal, even if you're currently outside the United States.
Also, do keep in mind, many banks and apps have now banned the use of VoIP based numbers for receiving OTP SMS even within the USA. Some of these include:
1. WhatsApp
WhatsApp does not support VoIP numbers for registration. According to their Help Center:
"Unsupported phone numbers, such as VoIP, landlines, toll-free, paid premium numbers, universal access numbers (UAN), shared cost, and personal numbers can’t be registered on WhatsApp." WhatsApp Help Center
Additionally, Meta has disallowed VoIP numbers from registering and using the WhatsApp Business App.
2. Microsoft Azure
Microsoft Azure requires a valid mobile number for verification and does not accept VoIP numbers. As stated in their support documentation:Microsoft Learn+1Reddit+1
"A Voice-over-IP (VoIP) phone number can't be used for the phone verification process."
Do check the terms and conditions or privacy policy of your app or bank before trying to register your number with them as they may not allow it.
Our other virtual numbers, such as UK numbers are not as prone to this type of restriction.
