Marketplace Fees Are Only One Part of the Sale

One of the most common reseller mistakes is treating the marketplace deduction as the complete cost of selling.

Imagine you sell an item for £40 and the platform takes £4.

That does not mean you made £36 profit.

You may still need to subtract:

• the amount you paid for the stock;
• postage;
• packaging;
• preparation or repairs;
• advertising;
• storage or fulfilment;
• other transaction-specific costs.

The Main Types of Marketplace Fees

Before calculating anything, identify how the platform charges you.

What Amount Is the Percentage Fee Applied To?

This is where many manual calculations go wrong.

A marketplace percentage is not always calculated only against the item price.

Depending on the platform, the fee base can include:

• item price;
• postage paid by the buyer;
• gift wrapping;
• discount treatment;
• taxes in certain calculations;
• other amounts defined by the platform.

Seller Fees and Buyer Fees Are Not the Same Thing

Some marketplaces increasingly use buyer-side charges as part of their business model.

A buyer fee should not automatically be subtracted from the seller’s payout as though it were a seller commission.

But that does not make buyer fees irrelevant.

If the buyer sees:

• £30 item price;
• plus postage;
• plus marketplace protection or buyer fees;

their actual checkout cost may be materially higher than the headline listing price.

That can affect offers, conversion and the maximum price buyers are willing to accept.

Remember VAT on Marketplace Services

Some marketplace fee schedules are presented before VAT, while other charges are already stated as VAT-inclusive.

This makes copying a percentage from a fee table and treating it as the final cash cost potentially misleading.

For example, eBay’s underlying UK Regulatory Operating Fee for business sellers is 0.35%, and eBay explains that VAT on that fee can produce a 0.42% VAT-inclusive cost.

TikTok Shop, by contrast, currently describes its standard UK platform commission as inclusive of applicable taxes including VAT.

Six Marketplace Fee Models at a Glance

Optional Costs Can Be Larger Than the Standard Marketplace Fee

The standard transaction charge is not always the biggest platform cost.

Advertising

eBay Promoted Listings, Amazon Ads, Etsy Ads and other paid-placement systems can reduce the contribution left from each order.

If advertising is genuinely required to produce the sale, include it when evaluating the product.

Boosted Listings

A Depop sale attributed to a Boosted Listing can have dramatically different economics from an organically generated sale.

Affiliate Commission

TikTok Shop sellers working with creators need to account for the agreed commission separately from the standard platform charge.

Subscription Costs

Monthly marketplace plans are business overhead rather than necessarily a direct fee on one transaction.

For decision-making, you can allocate an approximate monthly subscription cost across your expected sales volume.

International and Currency-Conversion Costs

Cross-border sales can introduce additional fee layers.

Depending on the platform and transaction, these may include:

• international marketplace fees;
• currency conversion;
• cross-border fulfilment;
• customs or import-related costs;
• different payment-processing treatment.

If a transaction is cross-border, do not assume the fee model is identical to a normal UK domestic sale.

Buyer-Paid Postage Is Not Automatically Profit

If a buyer pays £4 for delivery and you spend £3.50 on the carrier, your shipping economics are not simply a £4 gain.

In addition, some platforms include customer-paid postage within the amount used to calculate percentage-based fees.

Keep these two figures separate:

• postage charged to buyer;
• your actual shipping cost.

SellerStack’s UK Shipping Cost Comparison Calculator can help test delivery scenarios before you set the listing price.

How to Calculate True Net Profit

Once the marketplace fee has been calculated correctly, move to the full transaction.

A useful general model is:

Worked Example

Assume:

• item price = £30;
• buyer postage = £3;
• total revenue = £33;
• percentage marketplace fee = 10%;
• fixed marketplace fee = £0.40;
• stock cost = £8;
• actual postage = £3.20;
• packaging = £0.40.

Do Not Stop at the Profit Amount

Two products can produce the same £15 profit while being very different investments.

Profit Margin

Margin measures the share of revenue remaining as profit.

A simplified formula is:

Profit Margin = Net Profit ÷ Revenue × 100

Return on Investment

ROI looks at the profit generated relative to the money invested in the stock.

That can be particularly useful when comparing two sourcing opportunities requiring very different amounts of capital.

Use the Reseller ROI Calculator when the question is not simply “how much profit?” but “how efficiently is my stock money working?”

How to Calculate Break-Even Properly

The old shortcut:

Stock + Shipping + Packaging + Estimated Marketplace Fee

can be misleading when the marketplace fee itself is calculated as a percentage of the selling price.

If you lower the selling price, the percentage fee also changes.

So the percentage needs to be solved as part of the equation.

Break-Even Example

Suppose your costs excluding marketplace fees are £11.60, the fixed platform charge is £0.40 and the percentage fee is 10%.

Required break-even revenue:

(£11.60 + £0.40) ÷ (1 − 0.10) = £12 ÷ 0.90 = £13.33

At approximately £13.33 of fee-bearing revenue, the sale recovers those entered costs without producing a profit.

Work Backwards From the Profit You Need

Break-even tells you the minimum needed to avoid a loss.

A business usually needs more than break-even.

If you want to calculate the selling price required to cover costs and generate a target profit, the logic becomes:

Required Revenue = (Costs + Fixed Fee + Desired Profit) ÷ (1 − Percentage Fee)

That is the logic behind SellerStack’s Product Pricing Calculator .

How to Compare the Same Product Across Marketplaces

Marketplace comparisons become useful only when the assumptions are consistent.

Start with the same:

• product;
• purchase cost;
• condition;
• packaging cost;
• realistic expected selling price;
• seller-side fulfilment costs.

Then change only the marketplace-specific elements.

Does the Marketplace With the Lowest Fees Produce the Most Profit?

Not necessarily.

Suppose:

• Marketplace A costs £2 in seller fees and sells the item for £25.
• Marketplace B costs £5 in fees but supports a £35 selling price.

Marketplace B may still generate more net profit.

The outcome also depends on how quickly the product sells and how much seller work each transaction requires.

Browse the SellerStack Marketplaces Hub when the question has moved from “what are the fees?” to “which marketplace actually fits this product?”

Marketplace Fees Should Affect Your Buying Price

Fee calculations are useful before listing, but they become even more valuable before you buy the stock.

If a product’s expected selling price cannot comfortably cover:

• marketplace fees;
• stock cost;
• fulfilment;
• packaging;
• the profit and ROI you require;

then the real problem may be the buying price.

Our guide to how much to pay for resale stock explains how to work backwards from the expected sale.

12 Common Marketplace Fee Calculation Mistakes

Which SellerStack Calculator Should You Use?

Marketplace Fees UK: FAQs