How promo codes actually work, and why so many of them fail
A code that "doesn't work" usually isn't broken. It is expired, limited to certain products or one use per customer. Here is how to tell what is going on.
A promo code is a rule stored in a shop's system. Understanding the rules explains most failures.
The rule behind every code#
When you type a code at checkout, the shop's system checks conditions. The usual ones: a start and end date, a minimum basket value, certain products or categories only, new customers only, one use per customer, and whether the code can combine with other offers. If any check fails, the code is rejected, often with a vague message.
Why codes fail#
Expired. Dates pass and codes die, but they linger on coupon sites for years.
Excluded items. Sale items, certain brands and gift cards are often excluded.
Minimum spend. The code applies only above a basket threshold.
New customers only. The shop checks your email or address.
Not stackable. A sitewide sale price and a code often can't be used together.
Single use. Personal codes, such as ones sent after signing up, work once for your account.
Why aggregator sites are unreliable#
Coupon aggregator sites collect codes from many sources, and nobody removes them when the shop ends the offer. Some list codes that never existed to attract clicks. A site that says "validated" without saying how, when and by whom is giving you a label, not evidence.
Where genuine offers come from#
The shop's own website banner or promotions page.
The shop's newsletter signup, which often triggers a first-order code.
An affiliate network feed or partner programme the shop publishes through.
A bundle or subscription discount that needs no code at all.
What counts as proof#
A code is proven when someone has applied it at checkout and seen the price change, and recorded the date. A "last checked" date should be shown, and the code should be removed or labelled if it fails later.
What to do at checkout#
Read the conditions on the offer. Try one code at a time. If it fails, check the cart for excluded items before deciding it's dead. Never pay for access to a code, and never enter payment details on a site just to receive one.
How we handle it#
We list a discount only if it is visible on the store's own page or supplied by a source we can name, and we say when we last checked it. Where a store has no live offer, we say that instead of padding the list.