Phone call QR codes for signs, vans and windows

Reading a phone number off a van as it pulls away, or copying one from a poster across a car park, is how numbers get misdialled. The Phone call kind in QR by Zaweba removes the copying. You type the number, the app makes a code holding a tel: link, and when someone scans it their phone offers to dial it.

It is one of the simplest kinds of code, and one of the most practical for a sign.

Where a phone code earns its place

A phone code is useful wherever people are likely to call rather than browse. A shop window with the number for out-of-hours enquiries. The side of a van or a trailer. A sign on a gate, a notice in a lift, a poster for a lost cat, a card left on a car windscreen. In each case the person reading it may be standing up, in a hurry or wearing gloves, and pointing a camera is easier than typing eleven digits.

Because the number is the only thing in the code, the pattern is small and simple. That makes it a good choice for small labels and stickers, and for signs that will be scanned from a distance.

Entering the number

Type the number into the box, and enter it with its country code if people might scan it from abroad or with a phone registered in another country. For a UK number that means +44 followed by the number without its leading zero. A number written that way dials correctly from anywhere.

Leave out anything that isn't part of the number, such as a name or "call us on". If you want words, put them in print next to the code. Do write the number itself near the code as well, for anyone whose phone doesn't scan.

Checking it

The live preview reads the code back after every change and says Checked: it reads back exactly, or tells you why not, such as colours that are too close together or a margin that is too small. That proves the code is sound, but not that the number is right, so scan it with your own phone. It should offer to call the number, and you can cancel before it rings.

If you try to save a code that doesn't read back, the app asks first.

Making it fit the sign

Set the size in millimetres with the margin included. For a van or a window, bigger is better, because people scan from further away. Keep a decent margin of empty space around the code so scanners can find its edges, and keep the colours dark on light.

For a sign maker or a vinyl cutter, save as SVG, which is measured in millimetres and stays sharp at any size. PDF gives a one-page vector file the exact size of the code. PNG at 600 or 1200 dpi is fine for a printed poster. Copy picture pastes the code straight into a document.

Choosing between call, text and email

The Phone call kind sits next to the Text message and Email kinds, and each suits a different caller. A call is best for urgent jobs and people who want to talk. A text suits quick bookings and people who'd rather not phone. An email suits enquiries that need detail. Some businesses put two small codes side by side, one to call and one to text, with words under each.

Whichever you choose, the number in the code never expires, because it is stored in the code itself rather than on anyone's server.