Getting apps to send you an SMS verification code can be tricky depending on where you are based.
There are key tips to getting the app to send an SMS to your 2ndNumber, especially if you are based overseas and you are not in the country of origin for your 2ndNumber (eg. you have a US number and live in India for example):
Tip 1: Use a VPN if you can
You don't need a VPN if you are in the country of origin of your 2ndNumber (eg. you're in the US or UK and have a respective US or UK number), and generally speaking, not if you are in Europe. However, if you're based over in Asia, Africa or South America, you might want to try a VPN - connect to the VPN then restart the app and attempt an SMS verification.
Tip 2: Use voice activation if available
If the app allows you to make a call instead of receiving an SMS, try that method - just make sure you have the webphone open in order to receive the call.
Tip 3: Sign up during working hours of the app in question
If you're using a US app, eg WhatsApp, then sign up during working hours in the US - likewise if it's a UK app, signup during UK working hours. Signups outside of working hours are "red flagged" IF you're not based in the country of origin of the app.
Tip 4: Wait 24 hours AT LEAST
Don't try to sign up before 24 hours at least - this is because US numbers need to be registered on the ROBOCaller Mitigation Database and some apps will check this before allowing you to sign up. It can take longer than 24 hours for your number to show on the datbase over weekends and holiday periods, so keep that in mind.
Tip 5: Check local laws
If you live in a country with strict privacy laws, many apps are obliged to honour those laws and will restrict or block signups from those countries.
The following countries are known to block VoIP calls and SMS messages sent to their citizens over the national phone operators:
- North Korea
- Saudi Arabia
- United Arab Emirates
It's worth pointing out that this list can change and most of these measures are a direct result of anti-terrorism legislation in these respective countries. As this legislation changes, so will the list.