It's easy to look at a sale and think: bought for £40, sold for £70, that's £30. But by the time the money lands in your bank, it's usually a lot less. Knowing the real number is the difference between a business that grows and one that just keeps busy.
Start with what it really cost you
The cost of an item isn't just its price. Add the delivery you paid, and if one delivery charge covered five items, split it across all five. Add any buyer protection or service fee too. That's your true cost per unit.
Then take off the selling costs
Marketplace fees come first: a percentage of the sale, often plus a fixed amount per order. If you promoted the listing, the ad fee comes off as well. Then the postage label you bought, and any packaging or other costs for that sale.
Put it together
Real profit = sale price − marketplace fees − ad fees − postage − other selling costs − true cost of the items. Do this for every sale and the monthly total is a number you can trust, and the one that matters at tax time.
Let the app do the sums
Flipdesk takes eBay's real fees (including Promoted Listings ad fees) from eBay itself, splits delivery across multi-item orders, and works out profit for every sale automatically. Sales that don't have a cost yet are flagged, so the total is never quietly wrong.