Everyone makes these. The smart ones make them once.
There's no reseller alive who hasn't lost money on a bad lot or trusted the wrong supplier. But some mistakes are so common and so avoidable that it's worth talking about them before they cost you.
1. Buying stock before knowing what it sells for
Before you buy any lot, spend 20 minutes on eBay's sold listings. Filter by completed sales and look at what things actually sold for — not what people are asking. If the numbers don't work on paper, they won't work in reality.
2. Ignoring all the costs
Real profit is: selling price minus cost price minus platform fees minus postage minus packaging minus returns. Platform fees alone are 12-15% on eBay. Use the Profit Calculator before you buy, not after.
3. Paying by bank transfer to a new supplier
Bank transfer to an unknown supplier is the highest-risk payment method there is. Once it's gone, it's gone. Legitimate suppliers accept card or PayPal Goods and Services. Anyone insisting on bank transfer for a first order is a red flag.
4. Buying too much too soon
Always test before you scale. Buy the smallest quantity that makes sense, prove you can sell it at the margin you expect, then go bigger. Every experienced reseller has a horror story about a garage full of stock they couldn't shift.
5. Underpricing out of fear
Price what the market supports, not what makes you feel safe. Check sold comps, price competitively but not desperately. If stock isn't selling, the answer is usually better photos or a better title — not a lower price.
6. Giving up after a bad show or bad lot
Every reseller has a show where nothing sells. Treat these as data points, not disasters. What didn't sell? Why? Each bad result is telling you something useful if you're willing to listen.
7. Not keeping records
HMRC has a trading allowance of £1,000 per year — above that you need to declare income. Keep a simple spreadsheet from day one: what you bought, what you paid, what you sold it for. It takes five minutes per lot and saves enormous headaches later.
8. Selling fakes without knowing it
Counterfeit goods are everywhere in the wholesale market. Selling fakes can get your accounts suspended and in serious cases lead to legal action. If a deal looks too good to be true on branded goods — it is.
9. Not asking for help
The UK reselling community is one of the most generous there is. Groups like Whatnot Seller UK are full of experienced sellers happy to help. Ask questions. Learn from people who've made the mistakes already.
10. Waiting until everything is perfect
You don't need a ring light, a professional camera, or a fully stocked inventory. Start messy and get better. The resellers making real money right now didn't wait until they were ready.