When Dynamic QR Codes Stop Working: Trials, Cancellations and Scan Caps

A Dynamic QR Code Stops Working When Its Redirect Does

A dynamic QR code is a code that encodes a short link belonging to the provider, which redirects to wherever you currently point it. A static QR code is a code whose destination is stored in the pattern itself, so no server sits between the scan and the page. Only the first kind can be switched off, because only the first kind has a server in the chain that can be told to stop.

A redirect is the answer a server gives when a short link is opened, telling the phone which address to load instead. Every scan of a dynamic code is a request to the provider's server for that answer, and the provider decides, on every request, whether to give it. That decision is where the five failures live. Nothing in the printed pattern changes; what changes is the answer.

This is also why a dead dynamic code is so hard to diagnose from the object. The code scans. The camera detects it, decodes it and offers to open a link, exactly as it did the day it was printed. The failure only appears after the tap, on the provider's server, where the person holding the phone cannot see it and the person who printed the code is not standing.

Four of the five triggers are the provider's decision, taken on their timetable. A trial ends on the day the trial was set to end, whether or not the print run is finished. A scan cap is reached on whatever day the two-hundredth or the thousandth customer scans. The only one you pull yourself is the deleted link, and even that one, once the paper is in circulation, cannot be pulled back.

Five Ways a Provider Switches a Printed Code Off

The five triggers are a trial ending, a subscription lapsing, a scan cap, an advertising tier, and a deleted or retired link. Each vendor publishes which of the five it applies, and the rules differ enough that the same printed code lasts weeks on one platform and indefinitely on another. The table gives the vendors' own rules, with the date each was read, because pricing and policy pages move.

Two things stand out in the column of rules. The first is that "free" means a different thing on every row: a lifetime cap of 100 scans, a monthly allowance of 1,000, a two-week clock, a code that works but shows someone else's advertisement first. The second is that cancellation is not one policy either. Hovercode keeps the first three codes alive and switches off the rest; QRCodeChimp keeps the ten most recent; Uniqode and Scanova keep none. Which of your printed codes survives depends on the order you made them in.

The advertising row is the one that never shows up in testing. The code resolves, the page opens, and the person who printed it sees their own page every time they check. The customer sees an advertisement first. ME-QR states that its free dynamic codes do this; QR Tiger's free dynamic codes do the same. A code that works for you and shows an advert to everyone else is not broken, but it is not the code you thought you had printed.

The Print Outlives the Trial by Years

A trial is measured in days and a print is measured in years, and a dynamic code on a trial works for the shorter of the two. Scanova's trial is 14 days; QRFY's is 7. A table card in a restaurant stays on the table for a year or two, a sticker on a product for the life of the product, a vehicle wrap for three to five years. A code printed during a trial and never upgraded works for 1% to 4% of the time it is in use.

A scan cap is the same mismatch measured in people instead of days. Unitag's public generator deactivates a code after 100 scans. A code on a shop counter that is scanned twenty times a day reaches 100 scans in five days; QR Tiger's 500-scan ceiling lasts 25 days at that rate; QRCodeChimp's 1,000 scans a month covers it, until a busy month. The cap is reached fastest on exactly the codes that are working best, which is the opposite of what a limit is usually for.

The cost of a switched-off code is not the subscription that was not paid. It is the print run that has to be collected and redone, and the customers who scanned a dead code in the meantime and will not scan the next one. Neither appears on the provider's pricing page, because neither is a cost the provider bears.

The arithmetic cuts both ways, and it is worth saying so. A dynamic code behind a two-week campaign poster is well served by a two-week trial. A code on a laminated menu, a product label or a sign is not served by a trial at all, and is only served by a subscription if the subscription will outlive the object. The question to answer before printing is how long the object will be in use, and the subscription post runs that arithmetic for several kinds of object.

What the Person Scanning Sees

A person scanning a switched-off dynamic code sees the provider's page, not yours. Depending on the trigger, that page is an error, a notice that the code is inactive, an invitation to the account holder to upgrade, an advertisement, or nothing at all while the phone waits for a server that no longer answers. In every case the code itself scanned normally a moment earlier.

The person scanning cannot tell you. They do not know who printed the code, the provider's page does not say, and the natural conclusion from a dead link on a menu is that the restaurant did not bother, not that a trial ended on a server in another country. So a switched-off code produces no complaint, which is why so many of them stay on tables and walls for months.

A static QR code fails differently, and the difference is the point. A static code's destination is in the pattern, so the only server in the chain is yours. If your page is up, the code works; if your page is down, every link to it is down and you will hear about it from somewhere else. There is no third party whose timetable or pricing can intervene. Do QR codes expire separates the four things people mean when they say a code has expired, and the static kind is only subject to two of them.

How to Tell Whether a Printed Code Can Be Switched Off

Read the code, not the marketing. A QR code encodes a string of characters, and the hostname in that string says who can switch the code off. The check takes two minutes and works on a code you printed years ago as well as on one you are about to print.

1. Decode the code without opening it. Photograph the printed code or open the original file, and drop it into the QR code decoder. It shows the exact string inside the pattern without following any link.
2. Read the hostname. If the string is your own domain, a message, a Wi-Fi login or a contact card, the code is static and nobody can switch it off. If it is a short link on a domain you do not own, the code is dynamic and the owner of that domain decides whether it keeps working.
3. Find the owner's published rules. On the provider's pricing or FAQ page, look for three things: whether the plan is a trial and when it ends, whether there is a scan cap and whether it is monthly or lifetime, and what the provider says happens to codes when a subscription is cancelled.
4. Check the account the code belongs to. Log in and confirm the plan is active, the code is not marked inactive or paused, and the email address on the account is one somebody still reads. Renewal failures and trial-end notices go to that address and nowhere else.
5. Scan a printed copy with a phone that has never seen the page. Use a phone that is not logged in to anything of yours, on mobile data rather than the office Wi-Fi. That is what a customer's scan looks like, and it is the only way to see an advertisement or an upgrade prompt that the account holder is spared.

For a code that is still at the design stage, add one line of insurance: print the destination's readable address beside the code. A short, human-readable URL next to the symbol costs nothing, and it is the one thing on the object that keeps working when the redirect behind the code does not. The print checklist covers where to put it.

What to Do When a Code Has Already Stopped

A switched-off dynamic code is revived by the provider or replaced by a reprint; there is no third option, because the hostname in the pattern belongs to the provider. Which of the two applies depends on the trigger, and on what the provider does when the account comes back.

• After a trial or a cancellation, subscribe again. Hovercode states that codes made inactive by a cancellation reactivate on resubscribing. Scanova states that dynamic codes require an active subscription to keep working, which implies the same in reverse. Check the vendor's own wording before paying: a provider that deleted the code rather than pausing it has nothing to reactivate.
• After a scan cap, upgrade or wait. A monthly allowance, like QRCodeChimp's 1,000 scans, resets; a lifetime cap, like Unitag's 100, does not. A capped code on a free plan is usually revived by moving to a paid plan, and the same printed code then works again.
• After a deletion, reprint. A deleted link is gone. Bitly states that a deleted link and its QR codes are removed permanently. The printed material has to be replaced, and this time with a code whose destination you control.
• If the code was static, fix the destination. A static code that has stopped opening anything has a dead page behind it, not a dead redirect. Restore the page or redirect the old address at your own web host, and every printed copy works again without being touched.

Replacing a dead dynamic code with a static one is the permanent fix, and the static code can still be made editable in the one way that does not depend on a QR vendor: point it at a short path on a domain you own and change the redirect at your host. The subscription post describes that arrangement step by step. Until KoloQR's own dynamic codes launch, the generator makes the static kind, free and with no account.

What KoloQR's Dynamic Codes Do Instead

KoloQR is adding dynamic QR codes, and the launch commitment is the opposite of the table above: when a subscription ends, every dynamic code keeps redirecting to the last destination it was given. Editing and new analytics pause until the subscription is restarted; nothing that is printed is switched off, no code is deleted, and no short link is reassigned.

There is no scan cap on any plan and no advertisement between the code and the page. The plan is $9 a month, billed monthly and cancelled at any time, and the waitlist gets the first month free at launch. The dynamic QR code generator page carries the full policy, the analytics the dashboard reports, and the sign-up.

None of that changes the advice above for a code you print today. A dynamic code is only as durable as the policy behind it, whoever the provider is, so read the policy before the print run and print the readable address beside the code. A static code from the generator needs neither precaution, because there is nobody who can switch it off.