QR codes in advertising: on vehicles, signs and flyers

In short: a QR code works where people stop, such as at the sign by the entrance, on the flyer in their hand or on the parked vehicle. It needs enough size for the reading distance, a clear quiet zone, strong contrast, and it leads to a matching page, not the home page. There is no standard for the minimum size, only rules of thumb. So: test on a proof print.

We print and plot QR codes on film, signs and vehicles. This article sums up what we have learned, and what the QR code's developer, DENSO WAVE, says about it. As of October 2026.

Where a QR code makes sense

Scanning takes time: take out the phone, open the camera, aim, wait. People only do it when they are standing or sitting anyway and are curious. Good places are:

• Signs at the entrance, shop windows, site fences: anyone standing in front has time. For example for opening hours, a booking calendar or a service that doesn't fit on the sign.
• Flyer, business card, invoice: the paper is in hand, the distance short. Good for the link to your Google reviews, for example.
• Trade fair stand and sales counter: people waiting in a queue are more likely to scan.
• Company vehicle, when it is parked: outside the job site, in the customer car park. Nobody scans in moving traffic, and nobody should reach for their phone there.

Less suitable are places people drive or walk past, such as roadside posters or signs mounted high up. There, a short, legible web address counts for more than a code.

Where the code leads

The most common mistake is a code that leads to the home page. Someone who read “bathroom renovation” on the van wants to get to bathroom renovation, not to the menu. Better is a dedicated page that picks up exactly the topic of the advertising medium, with the phone number and enquiry button right at the top. How such a page is built is covered in the article create a landing page.

A dedicated target page per advertising medium has a second advantage: you can see whether the code is used. More on this in the article measuring marketing success. And the page must work well on a phone, because scanning always happens on a phone.

How big a QR code needs to be

DENSO WAVE does not give a fixed minimum size. It depends on how much data the code contains, how finely it is printed and from what distance it is scanned. As a technical lower limit, DENSO WAVE gives a smallest printable module, i.e. a square, of about 0.17 mm for a typical laser printer (DENSO WAVE: QR Code FAQ). That is irrelevantly small for advertising.

A common rule of thumb among QR code providers is that the code should be about one tenth of the reading distance. A code with 1 cm sides can then be scanned from around 10 cm, one with 10 cm sides from about a metre. That is not a standard but a rule of thumb. The more data in the code, the finer the squares and the larger it should be. That is why a short address pays off.

For a vehicle that someone walks past on the pavement, that quickly means codes of 15 to 20 cm. Always check on a proof print from the distance it will later be scanned from.

Quiet zone, contrast and colour

• Quiet zone: the code needs a clear margin of four modules all round, without text, lines or images (DENSO WAVE: how to use). Placing the code too close to the edge of a sign or a vehicle panel risks misreads.
• Contrast: DENSO WAVE basically recommends black on a white background. Other colour combinations should be tested thoroughly first. A red code on a white background cannot be read by scanners that use red light.
• Light on dark: we found no statement from DENSO WAVE on inverted codes, i.e. white squares on a dark background. Many phones read them, but not all devices. If you use them, test with several phones.

A logo in the middle is possible because QR codes have built-in error correction: part of the code can be missing or covered and it still reads. According to DENSO WAVE, level M, which compensates for about 15 percent, is most often chosen; level Q compensates for about 25 percent (DENSO WAVE: error correction). So a logo uses up reserve. The bigger the logo, the higher the level should be, and the more important the test.

Material and surface

From our workshop: glossy surfaces reflect, and a reflection over the code makes it hard to read. For outdoor codes we therefore like to use matt film or matt-laminated prints. On vehicles we avoid swage lines and strong curves, because the code gets distorted there. Flat areas on the side or rear are better. And a QR code fades too. A code hanging in the sun for years should be printed on lightfast material. Suitable material and installation can be found under vehicle graphics and signage.

Security: codes that can't be stuck over

Fraudsters stick their own QR codes over genuine ones, leading to fake pages. Austria's Watchlist Internet calls this “quishing” and advises checking whether a code is stuck over something else or is part of the original print (Watchlist Internet: quishing, German). Germany's Federal Office for Information Security recommends checking the address before opening it (BSI: quishing, German).

For advertisers this means: integrate the code into the print or the lettering where possible, rather than adding it as a separate sticker. And write the address legibly next to it. Then everyone can see where the code leads, and anyone who doesn't want to get out their phone can type it in.

Test before printing

Modern phones read QR codes directly with the camera app, on the iPhone as well as on current Android devices such as Google Pixel (Apple Support, Google Pixel Help). Still, test with several devices, including an older one, and in poor light. And check that the target page really is reachable. A code leading to a deleted page is worse than none, and vehicle graphics last for years.

A painter at the site fence

The case is constructed, but typical. A painting business has a small QR code on the driver's door that leads to the home page. It is never scanned. When the van is relettered, the code moves to the side panel, gets much bigger and leads to a “façade painting” page with photos and a call-back button. The short address is next to it. The business also hangs a site fence banner with the same code at every job. Neighbours walking past have time, and the target page shows how many actually scan it.

Our view

A QR code is no substitute for a clear message. On a sign or vehicle, it must first be legible who you are and what you do. The code is the offer to those who want to know more. That is why we plan it in during design, rather than putting it somewhere at the end. How advertising media and the website work together is shown in our overview marketing for small businesses.

Checklist

• Is the code where people stop?
• Does it lead to a matching page instead of the home page?
• Is it big enough for the reading distance, tested on a proof print?
• Does it have a clear quiet zone of four modules all round?
• Dark on light, with strong contrast, without reflections?
• Is it part of the print, with the address legible next to it?
• Tested with several phones, and will the target page stay reachable?

QR Code is a registered trademark of DENSO WAVE INCORPORATED.

Frequently asked questions

How big does a QR code need to be?

There is no fixed minimum size. It depends on the reading distance, the amount of data and the print. A common rule of thumb in practice is that a code should be about one tenth of the reading distance, so around 10 cm for 1 m. That is not a standard but a rule of thumb. Check the code on a test print from the distance it will later be scanned from.

Is a QR code on a company vehicle worth it?

Yes, if the vehicle is often parked: outside the job site, in the car park, in front of the shop. Then people have time to scan it. Nobody scans in moving traffic. There, a clearly legible web address or phone number matters more than the code.

What colour should a QR code be?

Safest is dark on a light background, ideally black on white. That is what DENSO WAVE, the company that developed the QR code, recommends. Other colours are possible but should be tested thoroughly first. A red code on a white background cannot be read by scanners that use red light.