How to start online arbitrage in the UK (2026 guide)

Online arbitrage is the version of Amazon arbitrage you can do from the sofa: you buy discounted products from UK retailers' websites and resell them on Amazon for a profit. No van, no store runs, no importing, and you can do it in the evenings around a job. This guide walks through exactly how it works in the UK, what you need, and how to make your first profitable buy without falling into the traps that catch most beginners.

What is online arbitrage?

Online arbitrage (OA) means buying a product from a retailer's website while it is discounted (a sale, a price drop, a voucher deal, a stacked promo code) and reselling it on Amazon at the normal selling price. Your profit is the gap between the discounted price you paid and what the item sells for on Amazon, after Amazon's fees come out.

It is the same game as retail arbitrage, just played online. In-store sourcing lives on clearance aisles and yellow stickers; online sourcing lives on price drops. UK retailers reprice constantly: flash sales, end-of-line reductions, multibuys, newsletter voucher codes. Every one of those events opens a gap for a while, and the whole craft of OA is being there while the gap is open. If you would rather start with the in-store side, our guide to starting retail arbitrage in the UK covers that end to end; the two work well together and most UK sellers end up doing both.

Is online arbitrage worth it in 2026?

Yes, with the same caveat that applies to every flavour of arbitrage: it rewards the sellers who check the numbers and punishes the ones who buy on a hunch. The margins on any single flip are usually modest, which is fine, because the model scales in a way store runs do not. You are not limited to the shops within driving distance, you can source at 11pm in your pyjamas, and a repriced product page is the same distance from every seller in the country.

The flip side is that everyone else can see the same product page you can. Speed and discipline matter more in OA than in RA: obvious deals get bought fast, and a listing that gets flooded with arbitrage sellers can see its price sag for weeks. The sellers who do well are the ones who spot drops early, judge them honestly, and pass on the marginal ones.

What you need to get started

• An Amazon seller account - The same account works for OA and RA. A Professional plan pays for itself once you sell more than a handful of items a month.
• A little starting capital - £100 to £300 is a genuine start. OA lets you buy one unit to test, so you never need to commit deep on an unproven product.
• A way to check deals properly - Before you buy anything you need the Amazon selling price, how often it sells, the exact fees, and your ROI. Guessing any of those is how beginners lose money.
• A way to catch price drops - This is the heart of OA and the section below deals with it properly. Deals are not evenly spread across the internet; they appear and disappear, and your sourcing method is really a method for noticing them in time.
• Somewhere to receive stock - Your own front door is fine to start. Parcels arrive, you check and prep them, and send them in to Amazon FBA (or post them yourself with FBM while you are small).

How OA sourcing actually works: catching price drops

Strip away the jargon and OA sourcing is one activity: noticing that a retailer or a brand has dropped a price below what the product sells for on Amazon, and buying while that is true. There are three common ways UK sellers do it.

1. Manual browsing

Work through the sale and clearance pages of UK retailer sites, checking anything promising against Amazon. It is free and it teaches you what a good deal looks like, which is genuinely valuable. It is also slow: you can lose an evening to two hundred products and come away with nothing, because you are looking in places where a drop may or may not have happened.

2. Paid leads lists

Services that email you a daily list of profitable finds, typically £30 to £80 a month. They save time, but every subscriber receives the same list, so popular leads get bought by dozens of sellers at once and the Amazon price can sag under the pile-on. Lists also cannot know your rules: your minimum ROI, your categories, the brands you are ungated in.

3. Catching the drops yourself, automatically

The third way is to have the price drops watched for you rather than hunted by you. This is the part of the job software is genuinely good at, and it is what the retailscout OA suitedoes: price drop feeds across UK retailers refreshed through the day, a Brand Radar that runs daily sweeps of the brands you choose to watch, a Retailer Radar that checks a chosen shop's sale stock twice a day, and harvested newsletter promo codes with expiry countdowns, because a code stacked on a drop is where OA margins get interesting. Every drop lands already priced against the Amazon UK sell side with fees and ROI worked out, and filtered to your own minimum ROI rather than a list-writer's. You are not buying someone else's finds; you are catching retailer and brand price drops as they happen, filtered to your own rules.

How to check whether an OA deal is worth buying

However a deal reaches you, the checklist before buying is the same five numbers:

1. The real selling price - Use the Buy Box price averaged over 30 to 90 days, not today's price. A spiked price that predates a rush of sellers is the classic OA trap.
2. How often it sells - Monthly sales tell you whether your units will move in weeks or sit for months. Slow sellers tie up the small pot of capital you are trying to compound.
3. Amazon's fees - Referral fee plus FBA fulfilment fee, exact, not estimated. They routinely take a third of the sale price and guessing them flatters every deal.
4. Your ROI - Profit as a percentage of your all-in cost, including delivery. Most sellers set a floor and walk away below it; our guide to what counts as a good ROI in arbitrage explains where to set yours and why OA floors are often a little lower than RA ones.
5. The competition - How many sellers share the listing, and whether Amazon itself is one of them. A deal that is fine with four sellers can be dead with forty.

If you use retailscout, this checking is built in rather than bolted on: every lead from the feeds and radars opens in the same deal analyser that prices in-store finds, with the sales data, exact fees, ROI and a 0-100 buy score already on screen. The finding and the checking are one motion, which matters in OA because the gap between spotting a drop and judging it is where deals get away.

A simple first-week OA workflow

1. Set your rules first: a minimum ROI, a minimum monthly sales figure, and a per-item spending cap.
2. Pick a lane you know: a category or a handful of brands you already understand as a shopper.
3. Check every candidate against the five numbers above, and let most of them fail. Passing on bad deals is the skill.
4. Buy one or two units of your best candidate. Small first buys make mistakes cheap.
5. Prep, send in, and watch what happens to the price and your sell-through before you rebuy deeper.

Common beginner mistakes in UK online arbitrage

• Pricing against a spike - The listing shows £29.99 today because a competitor briefly ran out. Buy against the 90-day average, not the best day of the year.
• Ignoring what happens when the discount ends - If ten other sellers caught the same drop, expect the Amazon price to dip when their stock lands. Build headroom into your ROI floor.
• Buying into gated brands or categories - Check you can actually list the product before you pay for it. Retailer receipts are not invoices, and some brands need approval you do not have yet.
• Forgetting delivery and consumables - Delivery to your door, poly bags, labels and prep time are all part of your buy cost. ROI on the sticker price is a fantasy number.
• Chasing every category at once - Depth beats breadth early on. Knowing ten brands well finds you more money than skimming a thousand products you cannot judge.

Online arbitrage and retail arbitrage work best together

Most successful UK arbitrage sellers do not pick a side. Store runs at the weekend produce finds no website will ever show you, and OA fills the evenings in between: the trips give you volume days, and between trips, the drops come to you. This is also the honest reason to prefer one membership over a stack of single-purpose tools: retailscout covers the OA suite and in-store sourcing across 15 UK retailers in the same £14.99 a month, with a 7-day free trial and cancel anytime, which is less than most sellers pay for a leads list alone.

The bottom line

Online arbitrage is the most accessible way into Amazon selling for anyone who cannot spend their days driving between shops: low starting capital, no geography, and deals that come to your screen. The sellers who make it work treat it as a numbers discipline, not a treasure hunt. Set your ROI floor, check the five numbers on every buy, start with single units, and put your effort into catching drops early rather than browsing endlessly. Do that consistently and OA becomes what it should be: a steady second engine for your Amazon business that runs from the sofa.