What a vCard QR does
The QR holds a vCard, the standard contact format phones already understand. Scanning it opens a prefilled new contact screen, and the person taps save. Nothing is looked up online, so it works with no signal.
Because the details are inside the code itself, they cannot be changed later. If your number changes, the printed cards are out of date. That is the trade for it working offline and forever, with no service that can disappear.
Keep it short
Every character makes the pattern denser, and a dense QR printed small on a visiting card is the usual reason these fail to scan. Include what someone genuinely needs: a name, one phone number, and either an email or a business name.
Leave out the long address and the note unless they earn their place. If you need to share more, point at a web page instead of packing it into the code.
Laying it out on a visiting card
- Keep the QR at least 2 cm across. Smaller than that and phone cameras start struggling under indoor lighting.
- Leave a clear white margin on all four sides. Do not bleed artwork into the pattern.
- Put it in a corner rather than the middle, so it survives being held.
- Dark pattern on a light background. Reversed or low contrast QRs fail often.
- Download the SVG for the printer. It stays crisp at any size.
- Print one proof and scan it with two phones before ordering the full run.
Adding a payment QR too
If you take payments, a second QR on the card is genuinely useful. The UPI QR code generator has a visiting card layout that sizes a payment QR for exactly this. Keep the two codes clearly apart and label each one, because two unlabelled QRs side by side is a guessing game.