What is the PayBox on Mirakl marketplaces, and how do you win it?

What is the PayBox?

On a Mirakl marketplace, each product has one page. Any approved seller can add an offer to that page with their own price, stock, delivery cost and lead time. The shopper sees one offer at the top, with the buy button, and the other sellers' offers further down. That top offer is the PayBox.

If a shopper clicks to buy and you hold the PayBox, you get the order. If a rival is cheaper, they get it. On a shared product the PayBox takes most of the sales, so holding it matters more than anything else about your offer. It plays the same role as the Buy Box on Amazon.

Who wins the PayBox on B&Q, Tesco, The Range and Argos?

On all four marketplaces the PayBox goes to the cheapest live offer on the product. A rival who lists a penny below you takes it. An offer that is out of stock or switched off doesn't count, which is why competitor prices should come from live offers only.

The four marketplaces differ in who can sell and how commission is set, which changes how far you can afford to move on price:

Because every marketplace is curated, the rivals on your products are usually established retailers and brands, and often the same businesses on more than one marketplace.

Why does losing the PayBox cost so much?

Losing the PayBox doesn't show up as an error. Your offer stays live, your stock is still there, and the product still appears in your catalogue. The orders simply stop. On a large catalogue, a handful of rivals undercutting you by a few pence on your best sellers can take a real share of your revenue before anyone notices.

The opposite mistake is just as quiet. If you hold the PayBox at £5 below the next seller, you're giving away £5 on every order that you'd have won at £4.99 more. Neither problem is visible from the seller portal alone, and checking hundreds of product pages by hand doesn't scale.

How do you win the PayBox back without losing margin?

Work through each product you've lost in the same order:

1. Find every rival on the product, not just the names you already know. Rivals can join a shared product at any time, and on newer marketplaces like Tesco and Argos new sellers are still arriving.
2. Measure the gap. Note who holds the PayBox now and how far below you they are, in pounds and per cent.
3. Work out the winning price: one penny below the cheapest live offer.
4. Check it against your floor. Compare the winning price with your minimum price and with your break-even after the marketplace's commission. If it's below either, don't move.
5. Make the change and check it worked. Rivals react, so confirm you hold the PayBox afterwards and keep watching the product.

Worked example (illustrative figures, ignoring VAT and delivery). You sell a cordless drill at £91.49. A rival lists it at £89.99 and takes the PayBox. The winning price is £89.98, a cut of 1.7%. With a cost price of £62 and a 15% commission (£13.50), you'd still make £14.48 a sale, so the move is worth making. If your cost price were £78, the same move would lose money, and the right answer is to hold.

When should you not chase the PayBox?

• When winning means selling at a loss. A sale below break-even is worse than no sale. Hold, and look at whether a lower cost price or a different delivery option would change the maths.
• When a rival keeps undercutting you. If every move you make is matched within hours, you're in a price war. Set a floor and stop at it, or the only winner is the shopper.
• When you're the only seller. You already hold the PayBox. The question is whether your price is too low, and a careful test of a few per cent higher can add margin with little risk.
• When you're already well below the next seller. Raise to just below the next price and you keep the PayBox while earning more on every order.

Why does PayBox history matter more than a snapshot?

A snapshot tells you who holds the PayBox now. History tells you how you got there: when a rival arrived on your product, what price they came in at, whether they drop prices at weekends or run out of stock every month. That context is the difference between reacting to every move and knowing when to wait. A rival who is regularly out of stock may hand the PayBox back without you cutting your price at all.

How PriceSynergy helps you win the PayBox

PriceSynergy connects to your shop through each marketplace's own Mirakl API and compares your price with every rival's live offer on every product you sell. Each product is marked as cheapest, joint cheapest, undercut or only seller, with the gap in pounds and per cent. Where you've lost the PayBox, it works out the winning price and flags it if that's below your min price or break-even, using the commission on your own order lines.

It also keeps 90 days of price and PayBox history per product, finds products where you can raise to just below the next seller, and on Growth and Scale lets you send approved prices to Mirakl, each checked against your min, max and break-even first. See how PayBox tracking works, or the marketplaces we support.

Questions sellers ask

Sources: Mirakl: B&Q launches marketplace on diy.com; ChannelX: Tesco Marketplace to replatform to Mirakl; Retail Gazette: The Range upgrades marketplace platform (April 2026); Sainsbury's: Argos is building a marketplace (February 2026). Marketplace names are trademarks of their owners. PriceSynergy is independent and isn't endorsed by any marketplace.