Retail arbitrage means walking shop aisles. Online arbitrage (OA) is the same idea from your laptop: buy discounted products from websites and resell them on Amazon for a profit. No driving, no trolley — just a browser, a spreadsheet-free way to check profit, and the discipline to only buy what actually makes money. Here's how it works in the UK in 2026.
Online arbitrage vs retail arbitrage
They're siblings. Retail arbitrage sources from physical shops; online arbitrage sources from websites. Everything downstream — matching to an Amazon listing, checking fees, reading demand, deciding buy-or-skip — is identical. If you're new to the whole concept, start with what retail arbitrage is and how it works; this guide is the online-sourcing version.
| Retail arbitrage | Online arbitrage | |
|---|---|---|
| Source | High-street shops | Retailer websites |
| Speed | One aisle at a time | Dozens of tabs at once |
| Extras | In-person clearance finds | Voucher codes, cashback, deal lists |
| Delivery risk | You own the stock immediately | Shipping delays, cancellations, price errors |
Most sellers do both — OA at the desk in the evening, RA on weekend shop trips.
Where UK sellers source online arbitrage stock
The principle is the same as in-store: ordinary branded products at temporarily silly prices. Common sources:
- Retailer sale and clearance pages — supermarket and high-street websites (Boots, Argos, supermarkets, department stores) run online clearance that often undercuts Amazon's marketplace price.
- Voucher codes and multibuy offers — a code or "3 for 2" can push a product below its maximum buy price even when the sticker price doesn't.
- Cashback portals — stacking cashback on top of a sale price quietly widens the margin.
- Brand outlet and end-of-line sites — end-of-season stock cleared cheaply.
You're not hunting rare products; you're hunting price gaps that appear and vanish daily across thousands of ordinary items.
How to check profit before you order
This is the whole game. For any product you need four numbers: the likely Amazon sale price, the referral fee for its category, the FBA fulfilment fee for its size and weight, and your delivered cost (price after codes/cashback, plus VAT if you're registered). Subtract fees, VAT and cost from the sale price for net profit; divide by cost for ROI.
Get the category referral rate wrong and every downstream number is wrong — the full picture is in Amazon FBA fees in the UK, explained, and sensible targets are in what's a good ROI and BSR. And read demand before buying: a great margin on a product that sells slowly is a sell-through trap that racks up storage fees.
The free Axivelo FBA calculator runs this exact maths for any product, and the Axivelo app does it from a barcode — useful when the parcels arrive and you're deciding what's worth sending into FBA.
The risks that are specific to online arbitrage
OA has a few traps that in-store sourcing doesn't:
- Price errors and cancellations — a website's "too good to be true" price sometimes is; orders get cancelled after you've planned around them.
- Shipping delays — stock in transit is money and time tied up; factor it in.
- IP and gating complaints — buying from an unauthorised source, or listing a gated brand, can trigger problems. Buy genuine stock from legitimate retailers and check gating before you order.
- Buying too deep — it's easy to click "order 50" online; size to about a month of the product's sales.
The honest summary
Online arbitrage is a real, legal, low-capital way into Amazon selling that scales better than shop trips because you can evaluate far more products per hour. But the leverage cuts both ways — it's just as easy to order fifty units of a loser as a winner. The sellers who profit check demand, fees, competition and price stability on every product before they order, and skip most of what they look at. Let Axivelo do the fee, VAT, profit and ROI maths so you can decide in seconds — free to start on Android — and sanity-check any single product with the free UK FBA calculator. New to selling on Amazon entirely? Start with the how to sell on Amazon UK guide.
Check any product before you buy
The free UK Amazon FBA calculator applies the 2026 fees and VAT to show net profit, ROI and margin. Axivelo does the same from a barcode scan in the aisle — free to start on Android.
Open the free FBA calculatorFAQ
What is online arbitrage?
Buying products cheaply from retailer websites — sales, clearance, voucher codes, cashback — and reselling them on Amazon at the higher price they sell for there. The profit is the price gap minus Amazon's fees, VAT and your cost.
Is online arbitrage legal in the UK?
Yes. Once a genuine product has been sold by the brand or with its consent, you're free to resell it (exhaustion of rights). You must sell genuine goods and describe them accurately, and some brands or categories on Amazon are gated and need Amazon's approval to list.
Is online arbitrage better than retail arbitrage?
Neither is better — they source the same way from different places. Online arbitrage lets you check far more products per hour from a desk; retail arbitrage can surface in-store clearance that never appears online. Many sellers do both.
How do I check if an online arbitrage deal is profitable?
Work out the Amazon sale price minus the category referral fee, the FBA fulfilment fee, VAT and your delivered cost after codes and cashback. That's net profit; divide by cost for ROI. A calculator or scanner app does it instantly so you can decide before ordering.
UK Amazon FBA sellers — we built Axivelo after one too many trips juggling Keepa, a calculator and a spreadsheet halfway down a B&M aisle. Now it shows profit, ROI, MAX PAY and demand on every in-store scan.