Only one of 201 products tracked in a Which? study of UK Black Friday deals was at its lowest price on the day, and 99.5 percent were the same price or cheaper at other times of the year. That single finding explains the most expensive Black Friday mistake: assuming the sale price is automatically the best price.
It is far from the only one. Below are ten errors that cost shoppers money, ranked roughly by how much damage they do, each with a fix. If you are still building your plan, begin with the Black Friday shopping guide for beginners and our holiday shopping budget planner. For the background on the day itself, see what Black Friday is.
The 10 Mistakes at a Glance
| # | Mistake | Fix |
|---|---|---|
| 1 | Trusting the ‘was’ price | Check price history first |
| 2 | Buying because of a timer | Use a pre-set ceiling price |
| 3 | Skipping the seller check | Search the seller name plus ‘complaint’ |
| 4 | Paying with a method that cannot be disputed | Use a credit card where possible |
| 5 | Ignoring shipping, tax and returns | Compare the final total |
| 6 | Using instalments or credit without a payoff plan | Only borrow what you can repay |
| 7 | Stacking small impulse buys | Keep to the written list |
| 8 | Buying a sale-only model by mistake | Match the model number |
| 9 | Not saving confirmations | Screenshot and store emails |
| 10 | Missing the return window | Note the return date at purchase |
Mistake 1: Is the ‘Was’ Price Real?
Often it is not the price you would have paid. Which? published its investigation on 23 November 2021, tracking 201 deals from 2020 across Amazon.co.uk, AO, Argos, Currys, John Lewis and Richer Sounds. It found that 92 percent were the same price or cheaper in the six months before, and 40 percent were cheaper at some point in the year. The study is UK-based and old, but the habit it exposes is universal. Use the steps in our price history tracker guide.
Mistake 2: Does a Countdown Timer Mean You Must Buy Now?
Rarely. Timers and ‘only 3 left’ badges are designed to compress your decision. Our fix, which is a suggestion, is to decide your ceiling in October, and when a timer starts, check only one thing: does the price meet the ceiling? If not, close the tab.
Mistake 3: Should You Skip the Seller Check?
Never, especially for brands you have not bought from. The Federal Trade Commission’s November 2025 alert says scammers may advertise brand-name products at unusually low prices, and recommends searching the seller’s name and website with words like ‘review’, ‘complaint’ or ‘scam’. Add our online shopping safety checklist to your routine.
Mistake 4: Which Payment Methods Are Hardest to Recover?
The FTC says that if a seller can only be paid with a gift card, wire transfer, payment app or cryptocurrency, it is probably a scam. It recommends credit cards where possible because you can dispute charges for double billing, items not received, or wrong or damaged goods.
Mistake 5: Why Do Shipping, Tax and Fees Catch People Out?
Baymard Institute’s research across 50 studies from 2006 to 2025 puts the average documented cart abandonment rate at 70.22 percent, and says extra costs such as shipping, tax and fees are the top reason, at 40 percent. Another 12 percent cite not seeing the total cost up front. Shoppers often find the surprise only at the last step. Compare final totals, not product prices, and check the return policy while you are there.
Mistake 6: Is Buy Now Pay Later Safe on Black Friday?
It can be if you can repay on schedule, and it is a trap if you cannot. Adobe measured 1.03 billion dollars of buy now pay later spending on Cyber Monday 2025, up 4.2 percent. Instalment plans make a purchase feel smaller than it is. Read our explainer on buy now pay later, and if you carry card debt already, see how to pay off credit card debt fast.
Mistake 7: Why Do Small Extras Add Up?
The National Retail Federation found that shoppers spent an average of 337.86 dollars each over Thanksgiving weekend 2025. Most of that is made of purchases that felt small. Keep a running total in your notes, and if an extra item is not on the list, replace something rather than adding it.
Mistake 8: Are You Buying the Same Model as the Sale Photo?
Be careful with unfamiliar model numbers. Retailers sometimes sell versions with slightly different specifications at sale time. This is our caution rather than a sourced finding, and the fix is simple: copy the model number from the tracker or manufacturer page and match it to the product page before you pay.
Mistake 9: What If You Do Not Keep the Order Confirmation?
The FTC says to save your receipt and order confirmation number to help recover money if something goes wrong. It adds that sellers must ship by the date they or their ads state, or give you a chance to get your money back. Create a folder in your email called ‘Black Friday 2026’ and move each confirmation there.
Mistake 10: How Long Do You Have to Return It?
Return windows vary by seller and product, and holiday purchases often have special terms. Read the policy before paying and note the last return date in your calendar. Baymard lists an unsatisfactory returns policy as a reason for 13 percent of abandoned carts, so shoppers clearly care about it.
What Is the Best Way to Avoid All Ten?
Use a checklist and a calendar. The dates are in our Black Friday 2026 timeline, and the category verdicts are in best Black Friday deals to wait for.
What Is a 60-Second Checklist Before You Pay?
| Check | Done? |
|---|---|
| The item is on my list | Yes or no |
| I checked its price history | Yes or no |
| The final total includes shipping and tax | Yes or no |
| I know the return window and the last return date | Yes or no |
| I am paying by a method I can dispute | Yes or no |
| The model number matches what I researched | Yes or no |
| I have searched the seller’s name plus ‘complaint’ | Yes or no |
| I will save the order confirmation | Yes or no |
If any answer is no, pause. This checklist is our own, built from the FTC, Which? and Baymard findings above. Copy it into your notes and use it for every purchase over a small amount.
