A QR code that opens a website is fine. A QR code that opens a pre-filled text message is a conversion.
I ran a campaign for a small restaurant last year. The check presenter had a QR code. Scan it, and a text message opened, addressed to the restaurant's number, pre-filled with "Add me to the waitlist for tonight." One tap to send. The restaurant built a text list of 600 regulars in eight weeks. They'd been trying to collect emails at the counter for two years and had 40.
The difference wasn't the channel. It was the friction. The QR code collapsed "open messages, type the number, type the words" into "scan, tap send."
The SMS QR Code
An SMS QR code encodes a string that opens the phone's text messaging app with the recipient number and message body pre-filled. The format is:
SMSTO:+15035550142:Add me to the waitlist for tonight
Scan it, the messaging app opens, the number is in the To field, the body is typed. The user reviews and taps send. They don't type the number. They don't type the message. They don't get the number wrong.
This is the entire value proposition. Pre-fill the work. Let the user just confirm.
Where SMS QR Codes Win
Anywhere you want a fast, low-friction action from a person standing in front of a physical object.
Restaurant waitlists, as above. Real-estate listing signs with a "text for more photos" code. Retail receipts with a "text FEEDBACK to get 10% off next time" code. Event posters with a "text REMIND to get a reminder the day before" code. Charity flyers with a "text DONATE 10 to give $10" code (where the carrier supports it).
The pattern: the user is already engaged enough to scan. The SMS code removes the last three taps between that engagement and the action.
The Email QR Code
An email QR code does the same for email. The format:
MAILTO:feedback@harvesttablefoods.com?subject=Packing%20feedback&body=I%20bought%20the%20winter%20soup%20and%20
Scan it, the email app opens with the recipient, subject, and body pre-filled. The user adds their thought and taps send.
Email is higher-friction than SMS (people are more protective of their inbox, and writing a longer message takes more effort), so it converts at a lower rate. But it carries more. A feedback email with the product SKU and purchase date pre-filled in the body gives you data you can act on. A text "FEEDBACK" gives you a phone number and not much else.
The One Mistake That Kills Both
People encode the full, raw string with no thought to the user's review step.
Here's the thing: a pre-filled SMS or email is not sent automatically. The phone opens the app, fills the fields, and waits. The user reads it and taps send. If your pre-filled message is a wall of marketing copy, the user reads it, feels marketed at, and closes the app without sending.
Keep the pre-filled body short. Two lines. A clear action. "Add me to the waitlist for tonight." "Send me the menu." "I'd like a quote for the deck project." The user taps send because the message is something they'd actually say. If you write the message for them, in their voice, they send it. If you write it in your marketing voice, they don't.
Compliance: Don't Be Creepy
SMS and email are regulated channels in most countries. A few rules.
Don't add people to a list without consent. A pre-filled "join" text is fine; the act of sending it is their consent. Auto-subscribing them because they scanned a different code is not fine and will get your number flagged.
Include the opt-out in any list you build. "Reply STOP to unsubscribe" is the standard. Carriers require it. Without it, your messages get filtered as spam and stop delivering.
For email, follow the rules in your jurisdiction (CAN-SPAM in the US, GDPR in the EU, CASL in Canada). The pre-filled subject and body are fine; the moment you store the address and email them again, you need consent, identification, and an unsubscribe link.
Tracking Without a Middleman
You'll see vendors selling "trackable SMS QR codes" that route scans through their server. They count scans, sometimes intercept the message, sometimes insert their own number. Avoid these for the same reason as dynamic URL codes: they create a dependency, they see your customers' messages, and they break if the vendor shuts down.
The clean way to track an SMS QR campaign is to use a dedicated number (yours or a rented one you control) and read the inbound logs. For email, use a dedicated inbox or an address with a plus-tag (like feedback+boxcampaign@yourdomain.com) and filter on the tag. You own the data, no vendor in the path.
Our QR code generator builds static SMS and email codes that go straight to the number or address you specify. Nothing routes through us.
A Real Example: The Real-Estate Sign
A friend sells houses. She put an SMS QR code on her yard signs: "Text for the full photo gallery." The code opened a text to her number, pre-filled with "Send photos for 412 Maple." She got the lead's number the moment they sent it. She replied with a link to the gallery. She closed two sales that started this way in the first season.
The code worked because the pre-filled message was something the buyer would actually type. "Send photos for 412 Maple." Six words. In the buyer's voice. Not "Hi! I'd love to learn more about this stunning property at 412 Maple, please send the gallery." That version doesn't get sent.
Size and Scanning
SMS and email QR codes are slightly denser than a short URL because the payload includes the number, the subject, and the body. Print at least 1.2 inches (30mm) for a short message, bigger for a longer pre-filled body. The same error-correction rules apply as any code: level M for clean environments, H for anything handled or weathered. See our error correction and sizing guide for the details.
The Short Version
Pre-fill the action. Keep the message in the user's voice, two lines, a clear ask. Use your own number or inbox, not a vendor's. Follow consent and opt-out rules. Print big enough.
Do that and a scan becomes a sent text, which becomes a customer, which becomes a sale.
