By: If you run a car dealership in Portugal, write about cars, or handle the books for a small business, you have probably heard the word "API" and assumed it was strictly for programmers. It doesn't have to be. This article explains, in plain language, what Clara Carros' free car-tax API is, what it does, and how you can use it even if you have never written a line of code.
What an API is, in plain words
An API is simply a way for one website or app to ask another for data, automatically. Think of a restaurant: the waiter takes your order to the kitchen and brings back your dish. You never step into the kitchen and you don't need to know how to cook. The API is that waiter: your site makes a request ("what's the import tax on this car?"), our API fetches the answer and hands it back in seconds, with nobody having to work out the calculation by hand.
What our API gives you, free and with no sign-up, in Portugal
The Clara Carros API is free, needs no registration and no access key, and allows around 60 tax requests per minute — more than enough for most uses. It returns data built for the Portuguese market:
- Import tax (ISV) — the vehicle tax you pay when bringing a car into Portugal. Endpoint:
/api/public/isv. - Market valuations — an estimate of a car's value. Endpoint:
/api/public/valuation. - Our car catalogue — the vehicles we have available. Endpoint:
/api/public/cars. - Canonical make and model lists — names written consistently, the same way every time. Endpoint:
/api/public/car_refs.
We also provide the annual road-tax (IUC) calculation through our calculators. You can see the ready-made tools on our ISV calculator and IUC calculator pages.
Who would want this, and why
The API isn't for everyone — it's for anyone who needs the same numbers, repeatedly and always correct. A few real examples:
- A dealer or importer who wants to show, next to each listing, what the ISV on that car would be — without calculating it by hand for every vehicle.
- A blogger or an accountant who needs to pull tax figures into a spreadsheet or an article, instead of copying them one by one.
- A small app or tool that helps people decide whether importing a car is worth it, by showing the tax cost on the spot.
What if I can't code? The no-code options
The good news: in most cases you never touch the API directly. We have ready-made alternatives:
- An embeddable calculator widget (iframe) — you paste a small block of code into your site and the calculator appears there, working. It's the simplest option.
- An SEO-friendly JavaScript version — similar to the widget, but with the content visible to Google, which helps your site get found.
- The official WordPress plugin — if your site runs on WordPress, you install the plugin and use a simple shortcode,
[claracars_isv], to drop the calculator onto any page. You can get the official plugin from the WordPress directory.
For the more technical — or if you work with a developer — we also provide the OpenAPI 3.1 specification, a ready-to-test Postman collection, and the open-source Python calculators (MIT licence) on GitHub. All of it is gathered on our developer API page.
An honest note
Yes, it really is free. In return, we ask just one thing: when you use the widget on your site, keep the attribution to Clara Carros visible. And we want to be clear about who we are — Clara Carros is a car importer and dealer in Portugal. We built these free tools because they are useful to us, and because we believe clear numbers help everyone make better decisions.
The calculator and tools give you the numbers. If you would rather we find, verify, import and deliver the car for you, see our turn-key import service and our car sourcing.
Frequently asked questions
Do I really not need to register or pay?
No. The API is free and keyless. You can start using it right away, within the limit of about 60 tax requests per minute.
I can't code. Can I still use this?
Yes. Use the embeddable widget, the JavaScript version, or the WordPress plugin. None of them require programming — you just paste a small block of code or use the [claracars_isv] shortcode.
Where do I learn more?
We have sibling articles on our MCP server for ChatGPT and other AI assistants, on the WordPress plugin, and on the Chrome extension that shows the ISV directly on mobile.de.