10 Common Mistakes UK Shoppers Make When Using Discount Codes

In 2025, the cost of living continues to rise across the UK, making savings more essential than ever for the average shopper. Whether you’re a busy parent managing household expenses or a student juggling a limited budget, voucher codes have become an indispensable tool for stretching every pound. With just a few clicks, you can access discounts on everything from food deliveries to fashion, electronics to travel.

But here’s the catch: many UK shoppers aren’t getting the full benefits of their discount codes. From using expired vouchers to missing out on app-only offers, small mistakes can lead to big missed savings. This comprehensive guide walks you through the 10 most common mistakes UK shoppers make when using voucher codes—and how you can avoid them to ensure you’re always getting the best deal.

Whether you shop online frequently or just occasionally, mastering the use of discount codes can unlock hundreds of pounds in savings every year. Let’s explore the key pitfalls and how to shop smarter in 2025.

1. Using Expired Voucher Codes

The Mistake: One of the most frustrating experiences is finding a seemingly perfect discount code—only to discover it expired yesterday.

Why It Happens: Many websites list outdated codes without regularly updating or verifying them. Additionally, shoppers may save a code to use later, only to forget the expiry date.

How to Avoid It:

• Use trusted UK voucher platforms like MomVoucherCodes.co.uk, which update their listings daily.
• Check the terms of the offer, including expiry dates and any conditions like minimum spend.
• Don’t wait too long to use a code—if you see a good one, act quickly.

2. Ignoring New vs Returning Customer Restrictions

The Mistake: Trying to use a ‘first-order’ discount when you’re already an existing customer.

Why It Happens: Many brands offer generous welcome discounts to attract new customers. However, these codes often won’t apply if the system recognises your email or IP address.

How to Avoid It:

• Read the offer details. If it says “new customers only,” it likely won’t work for repeat buyers.
• If allowed, you can try signing up with a different email or using a family member’s details.
• Consider loyalty programs instead if you’re a repeat shopper. Many brands offer rewards for returning customers.

3. Not Meeting the Minimum Spend Requirement

The Mistake: Applying a voucher that says “£10 off when you spend £50” when your basket only totals £45.

Why It Happens: Shoppers often get excited about a deal but forget to check the fine print.

How to Avoid It:

• Always review the voucher terms. Minimum spend thresholds are common.
• Add small, useful items (like socks or accessories) to meet the requirement without wasting money.
• Compare the offer to other available codes. Sometimes a 10% off code might be better for lower-value orders.

4. Trying to Apply Vouchers on Excluded Products

The Mistake: Attempting to use a code on a sale item or brand that’s excluded.

Why It Happens: Many shoppers skip the small print, assuming all items are eligible.

How to Avoid It:

• Carefully check exclusions. Commonly excluded items include sale goods, electronics, and gift cards.
• Some stores exclude popular brands (e.g., Nike, Apple) from percentage discounts.
• Look for brand-specific codes if you’re buying a high-demand item.

5. Entering the Code Incorrectly

The Mistake: Copying and pasting a code with an extra space or mistyping a single character.

Why It Happens: Discount codes are often case-sensitive and require exact formatting.

How to Avoid It:

• Always use the copy-paste method directly from trusted websites.
• Watch out for extra spaces at the beginning or end of the code.
• Double-check for zeroes vs. letter O, capital I vs. lowercase L, etc.

6. Applying the Code Too Late

The Mistake: Forgetting to enter the code before finalising payment.

Why It Happens: With features like one-click checkout and Apple Pay, shoppers often bypass the promo code field.

How to Avoid It:

• Always pause before clicking “Place Order” and check for a promo box.
• On mobile, you may need to tap “Show order summary” to reveal the field.
• Familiarise yourself with the checkout layout of frequently used sites.

7. Expecting to Stack Multiple Codes

The Mistake: Trying to use a 10% off code and a free delivery code at the same time.

Why It Happens: Some international sites allow code stacking, but most UK retailers do not.

How to Avoid It:

• Decide which code offers better value: % off, flat discount (£5 off), or free shipping.
• Some brands offer all-in-one codes that apply both a discount and delivery deal.
• Check the retailer’s FAQ to see their policy on combining offers.

8. Forgetting About App-Only or Member-Only Deals

The Mistake: Trying to use a discount that only works via the brand’s app or loyalty account.

Why It Happens: Shoppers often find codes online without realising the purchase must be made through an app.

How to Avoid It:

• Look for notes like “app-exclusive” or “members only” before using a code.
• Download the brand’s app (e.g., ASOS, Deliveroo, Trainline) to access app-only offers.
• Sign up for free loyalty programs to unlock exclusive codes.

9. Overlooking Newsletter or Loyalty Discounts

The Mistake: Skipping the pop-up offering 10% off for signing up to the brand’s newsletter.

Why It Happens: Many shoppers find pop-ups annoying and click them away quickly.

How to Avoid It:

• Take a moment to read the pop-up. Often, the discount code will be emailed immediately.
• Use a secondary email address for newsletters to avoid inbox clutter.
• Join loyalty schemes like H&M Club, Boots Advantage, or M&S Sparks for ongoing perks.

10. Using the Wrong Regional Code

The Mistake: Applying a discount code meant for US or EU customers on a UK website.

Why It Happens: Some global brands have separate codes per region, and affiliate sites may list international offers.

How to Avoid It:

• Check the domain (e.g., .co.uk vs. .com) before assuming a code will work.
• Use UK-specific voucher sites that prioritise local offers.
• Confirm that the currency and shipping region match your location.

Using voucher codes is one of the smartest ways to stretch your budget in today’s economy. But even the best codes won’t help if they’re used incorrectly. By avoiding these 10 common mistakes, you can take full advantage of every offer and keep more money in your pocket.

Whether you’re shopping for groceries, gadgets, holidays, or fashion, let MomVoucherCodes.co.uk be your trusted savings partner. We verify every code, flag expiry dates, and highlight exclusive deals you won’t find elsewhere.

Final Tip:

Before you hit that checkout button, take 30 seconds to:

1. Check if there’s a current voucher code.
2. Make sure it applies to your items and basket total.
3. Confirm it’s not expired or restricted.

Happy saving!