An SMS QR code opens the messaging app with your number and a pre-written text ready to send. It is a practical way to run keyword campaigns, appointment requests, feedback prompts or maintenance reports: the scanner sends a consistent message, so you always know what the enquiry is about. Enter your number with country code, write the default message, and download the PNG for signage or print.
The SMSTO format is widely supported on iOS and Android. Very old scanner apps may only show the raw text.
Yes. Always use the international format, for example +1 555 010 2233, so the code works for travellers.
Yes, they can change it before sending.