Short code
A short code is a 5- or 6-digit sender number used by businesses to send high-volume SMS such as verification codes; many virtual numbers cannot receive from short codes.
What is Short code?
A short code is a 5- or 6-digit sender number used by businesses to send high-volume SMS such as verification codes; many virtual numbers cannot receive from short codes.
Why it matters for verification
US and Canadian apps often send OTPs from short codes. Virtual ranges that cannot receive short-code traffic never get the message. Physical-SIM pools receive them normally.