A discount has to be funded by someone
Two promotions can show the same price to the buyer but leave the seller with different revenue. A seller-funded discount reduces the amount you earn. A platform-funded discount reduces the buyer’s payment while the platform provides the funded amount under the promotion’s rules.
Separate customer payment from funding
In the calculator, original price minus seller discount minus platform discount gives the item payment. Customer-paid shipping is added. The platform-funded discount is then added back to the commission base and seller revenue for this completed-sale estimate.
Use actual settlement values if a campaign has partial funding, a cap or another condition. Do not enter the entire discount as platform-funded unless the platform actually pays that amount.
The published commission example
TikTok’s UK policy demonstrates a £100 item with a £10 seller discount, a £10 platform discount and £5 shipping. The customer payment is £85. Adding the £10 platform-funded amount gives a £95 commission base. At the standard 9% rate, the commission is £8.55, including applicable fee taxes.
Affiliate costs are separate
A creator’s affiliate commission is another expense. Its rate and base should follow the relevant agreement and statement. Do not assume the affiliate base is identical to the platform commission base. The calculator provides separate fields so you can enter the appropriate amount.
Evaluate the whole campaign
Enter shipping service costs, seller promotion contributions and other effective costs. A campaign can increase sales while leaving less profit per order. Compare the promotion with your usual selling scenario using the same cost assumptions.
Confirm reduced rates
The published standard rate is 9%, but eligibility-based reductions exist. If Seller Centre shows a confirmed lower rate, enable the rate override. The tool does not assign a reduction simply because a product has a broad category name.
TikTok UK commission policy. Reviewed 14 October 2026. Your account statement remains the final reference.
Put the numbers to work
Try the Amazon UK FBA, eBay UK business or TikTok Shop UK calculator. Review every fee line and compare more than one selling scenario.