Why we built this
Marketplace fees change, VAT differs by taxpayer type, and with overseas sourcing the unit price alone never tells you the real cost. We kept making mistakes recalculating in Excel, so we turned it into tools. No sign-up, no payment, and your inputs are saved only in your own browser.
How we manage the numbers
- Source priority: official marketplace notices and seller centers first, then government sources such as the National Tax Service and Korea Customs Service, then reliable press coverage.
- Reference dates: every guide ends with its reference date and sources. Figures we could not verify are left out or marked as needing confirmation.
- One source of truth: fees and tax rates live in a single settings file, so when something changes the calculators and explanation tables update together.
- Regular checks: every rate is re-checked at least quarterly, and marketplace fee changes are applied as soon as they are announced.
What the tools can and cannot do
Results are reference values to help you decide. Actual settlements and taxes follow each marketplace’s seller center, Hometax and Korean customs. For important decisions such as tax filings, check with a tax accountant or customs broker.
Ads and affiliates
To keep the calculators free, bymay may show ads or affiliate links (such as Coupang Partners). Any area with affiliate links carries a notice right above it, and affiliations never affect calculation results or explanations.
Operator
- Business name: bymay · Representative Soohyeong Jang
- Mail-order business registration 2024-Busanjin-0367
- Questions and error reports: adminsoohyeong@bymay.co.kr
If you spot a fee change before we do, please email us. We will check and update right away.