How to use a voucher code at checkout

Last updated: 2 November 2026

Applying a discount code takes about ten seconds once you know where to look. Here is the whole process, plus the fixes for when a code will not go through.

Step by step

Fill your basket first. Add everything you want to buy before you think about a code. Some codes need a minimum spend to unlock.
Go to checkout and find the promo box. It is usually on the basket or payment page, labelled Promo code, Voucher, Discount code, Coupon or Gift card. On mobile it is often hidden behind a small "Add a code" link.
Paste the code exactly. Use the Copy button on our list so you do not mistype it. Some sites treat codes as case-sensitive.
Press Apply and check the total. The order total should drop, with the discount shown as its own line. If it does, you are done.
Rejected? Try the next code. Our lists put the code most likely to work first, so just work down the list. Trying another costs nothing.

Find a code for your store. No sign-up, no email, and every code is shown straight away.

Why a code gets rejected, and how to fix it

Minimum spend not met. Add a little more to the basket, or pick a code with no minimum.
New customers only. It will not work if you have ordered before. Look for a general code instead.
Excludes sale items. The code may only apply to full-price products in your basket.
Will not stack. If another offer is already applied, the code may be blocked. Remove the other offer and compare which saves more.
Expired. Codes come and go. Try the next one on the list; we refresh the lists daily.
Typo. Use Copy rather than retyping, and check for stray spaces.

Go for the biggest saving, not the biggest number

A "50% off selected lines" code can be worth less than "15% off everything", depending on what is in your basket. If a store has several codes, try the top two or three and keep whichever takes the most off your total.

Get the codes at checkout

The free Clerkenwell Coupons extension for Chrome shows the top codes for the store you are on, so you do not need to come back here to search. Same promise: no account, no tracking.

More guides

Best UK voucher codes: where codes come from and how we rank them.
Car-parts discount codes: Euro Car Parts, Autodoc, GSF and Halfords.