Quick answer: enter the phone number (with country code) and, if you like, the message people should send – for example “JOIN” or “Order 24”. The QR code uses the SMSTO: format, so the phone opens a new text message with both filled in. The person still chooses whether to send it.
What SMS QR codes are good at
Text messages don’t need data, an app or an account – which is why they still work for people that email and WhatsApp miss. Pre-filling the words makes replies consistent, so you can sort or count them easily.
- Opt-ins and keywords: “JOIN” to join a list, “STOP” to leave it.
- Polls at events: one code per answer, each with a different pre-filled word.
- Queues and pickups: “Table 9 ready to order” or “Car 4 – I am outside”.
- Reporting problems: “Broken light – Lamp post 1123” on street furniture or campus signs.
SMS charges
The person scanning pays their normal rate for one text message – often free within their plan. If you run a premium short code, tell people the cost next to the code; regulators in most countries require it.
iPhone and Android differences
Android camera apps and Google Lens open the message with the text filled in. Recent iPhones do the same through the camera’s banner. On some older phones only the number is filled in, so keep the message short enough that people could type it themselves, and print it next to the code: “Text JOIN to +44 7700 900123”.
Need the number saved, not just texted? A vCard QR code does that. If you also want calls, keep a separate phone call QR code next to this one so people can choose.
How to make an SMS QR code
- Enter the number. Use the full international format with + and country code, or your short code.
- Write the message. Keep it to a word or a short line – it is what people will send.
- Add a printed instruction. Put the same instruction in text next to the code for anyone whose phone does not pre-fill.
- Test and download. Scan with an iPhone and an Android phone, then download PNG, SVG or PDF.
Polls and votes with one code per answer
Print three codes side by side – “Vote A”, “Vote B”, “Vote C” – each sending its own word to the same number. Counting replies is then a matter of sorting your inbox or SMS gateway report by message text. Because every scan still needs the person to press Send, you get one deliberate vote per phone rather than accidental scans.
Characters, emoji and the 160 limit
Plain Latin text fits 160 characters in one SMS. The moment you add an emoji, Urdu, Arabic, Hindi or Chinese letters, phones switch to Unicode encoding and one message holds only 70 characters; longer texts are split and may cost the sender two messages. The counter under the message box shows your length against 160 – keep keywords plain and short.
Who pays for the text?
The person who sends it, at their normal rate (often free in their bundle). Short codes for marketing are regulated in most countries: say what people are signing up for and how to stop, for example “Text JOIN for weekly offers. Text STOP to end.”
Checklist before printing
- Send the message to the number yourself and confirm it arrives where it should.
- Print the same instruction as text: “Text JOIN to +44 7700 900123”.
- For marketing lists, include how to stop: “Reply STOP to unsubscribe”.
Frequently asked questions
Is the SMS sent automatically when someone scans?
No. The message app opens with the number and text filled in and the person presses Send. Nothing is sent without them.
Can I use a short code like 12345?
Yes. Enter the short code in the number box. Short codes only work inside the country they belong to.
What is the SMSTO format?
It is the standard way of writing a text message in a QR code: SMSTO:number:message. Most scanner and camera apps recognise it.
Can I make one code that texts several numbers?
Not reliably. Different phones handle multiple recipients differently, so use one number per code.
How long can the pre-filled message be?
Up to a normal SMS (160 characters) works best. Longer text makes the code denser and may be split into two messages.
Will people see my number?
Yes, the number appears in their messages app, exactly as if you had printed it.
Why does my message count drop to 70 characters?
Emoji and non-Latin scripts use Unicode, which fits 70 characters in one SMS instead of 160.
Can I use the code for two-factor or OTP texts?
No. One-time passwords are sent to the user by your system; an SMS QR code only helps people send a message to you.