Who this is for
If you write about EU VAT, e-commerce, OSS/One-Stop-Shop, or run an accounting/freelancer resource site, you can drop this interactive calculator straight into an article. Readers work out whether their cross-border B2C sales are still under the €10,000 threshold without leaving your page.
It's a native Web Component rendered in its own Shadow DOM, so its styles can't collide with your site's CSS and your CSS can't break it. No iframe, no build step, no external requests beyond loading the script itself.
How to embed it
Paste this where you want the calculator to appear:
<script src="https://oss-calculator.x1.kumavolt.dev/widget.js" async></script>
<oss-calculator-widget></oss-calculator-widget>
The <script> tag can go once anywhere on the page (e.g. before
</body>); place one <oss-calculator-widget>
tag for each spot you want a calculator.
Optional attributes
| Attribute | What it does |
|---|---|
home-country | Pre-select the seller's home country by ISO code, e.g. home-country="ES" (display only). |
prev-year | Pre-fill last year's cross-border total, e.g. prev-year="8500". |
<oss-calculator-widget home-country="DE" prev-year="0"></oss-calculator-widget>Live demo
This is the actual widget, running from the same widget.js the snippet above loads:
Terms & attribution
Free to embed on any site. The widget keeps a small "EU OSS €10,000 Threshold Calculator" credit link back to this project — please leave it in place. Like the main page, it's an indicative self-check aid, not tax advice: excise goods, multi-country stock, non-euro national thresholds, and Northern Ireland have exceptions the tool doesn't model. See the full calculator and disclaimer for details.