Few things at checkout are as annoying as a voucher code that won't work. You type it in, press apply and get "This code is not valid", or no message at all. This guide is for anyone who has hit that wall and wants to know why.
It groups the usual causes into problems with the code, problems with your basket and problems with how it was entered. There is also a short checklist to run before you give up, plus what to do if the order total looks wrong afterwards.
Why was my voucher code rejected?
Most rejected codes have expired, need a higher spend or don't cover something in your basket. Those three causes account for the large majority of failures. The rest usually come down to account history, typing errors or a glitch in the checkout.
The error message rarely tells you which one it is. That's why it helps to work through the causes in a set order, starting with the most likely.
Problems with the code itself
Sometimes the code is the issue, however well you set up your basket. These are the most common reasons.
The code has expired
Expiry is the biggest single cause. Retailers run promotions for short windows, sometimes just one evening, and switch the code off when it ends. A code shared on social media last weekend may already be dead. If a code is more than a few weeks old and has no end date, assume it has expired and look for a newer one.
It's for new customers only
Welcome codes only work on a first order. The checkout can recognise you by your email, account, delivery address or payment card. If you ordered once years ago, a welcome code will probably fail. Look for codes aimed at existing customers instead, which retailers often send through their newsletters and apps.
It belongs to someone else
Codes sent by email, printed on receipts or given through refer-a-friend schemes are often single-use and tied to one customer. Shared online, they look like any other code. They then fail for everyone else, or work once and stop. Fake codes behave in a similar way, and our guide to avoiding fake voucher codes and shopping scams explains how to spot them.
It's meant for a different channel or country
An app-only code may not work on the website. In-store codes won't work online, and a code from a retailer's Irish or US site won't work on the UK one. Student and NHS codes usually need you to arrive through the verification service's link, so the checkout knows you qualify. Our student discounts page explains how that verification works.
Problems with your basket
A valid code can still be rejected because of what's in your basket. These checks take seconds.
You're below the minimum spend
A code such as £10 off when you spend £50 is checked against the subtotal of eligible goods. Delivery never counts, and excluded items usually don't either. A £52 basket that includes a £5 gift card may only count as £47. If you're just short, adding a £3 item you'd buy anyway leaves you £7 better off.
An item is excluded
Exclusions often cover sale lines, gift cards, premium brands and some electricals. Some retailers reject the code if any excluded item is present. Others apply it only to eligible items, so the discount is smaller than you expect.
Here is an illustrative example. A £90 homeware basket holds a £40 lamp at full price and a £50 rug that is already in the sale. A 20% code that excludes sale items saves £8 on the lamp, not £18 on the whole order. If the code fails completely, remove items one at a time to find the one blocking it.
Another discount is already applied
Nearly every UK retailer allows one code per order. If a code was added automatically from an email link, a second one will be rejected. Look for a "remove" link next to the existing discount and keep whichever saves more. A code can often sit alongside a sale price or multi-buy, though, and our guide on combining sales and discount codes covers which pairings tend to work.
Typing errors and technical glitches
If the code and basket both look fine, the problem may be how the code was entered or how the site is behaving.
Lookalike characters and spaces
It's easy to confuse the letter O with zero, or the letter I with the number 1. Pasting can also add a hidden space at either end. Retype the code slowly and match the capital letters, since a few checkouts are case-sensitive.
Old sessions and blockers
Cookies, an old session, an ad blocker or an out-of-date app can all stop a discount applying. Log out and back in, rebuild the basket or try another browser. If you're sure the code should work, contact customer services with a screenshot before you order. Most retailers can't add a code after you've paid.
What should you check before giving up?
Run through this list in order. It covers almost every reason a code fails.
- Today's date falls within the code's published dates.
- Your eligible subtotal, without delivery, meets the minimum spend.
- Nothing in the basket is on sale or from an excluded brand.
- You qualify as a new customer if the code requires it.
- Every character is typed exactly, with no spaces.
- No other code or automatic discount is already applied.
- You're on the right site, country and channel.
- A fresh session or a different device has been tried.
What if the code worked but the total looks wrong?
Contact the retailer straight away if your confirmation email shows a different total from the checkout. Keep a screenshot of the basket with the discount applied. Most retailers will correct a genuine error or let you cancel.
For most online orders, the Consumer Contracts Regulations give you 14 days from delivery to cancel. The Consumer Rights Act 2015 also requires goods to match their description. If you paid by credit card for a single item over £100, Section 75 gives you a claim against the card provider too. For debit card payments, ask your bank about a chargeback.
Getting the right code first time
Most failed codes can be avoided before you reach the checkout. Use codes from the retailer's own emails and offers pages, or from sites that show where each code came from and when it ends. Read the terms for minimum spend and exclusions, then build your basket to suit.
Store pages such as Next and John Lewis show what each shop typically offers and the restrictions it tends to apply. Knowing that in advance means fewer surprises and more codes that work on the first try.