SmartCalcs Sales Tax API

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The easiest way to get accurate sales tax calculations.


A modern, robust API built for developers.

Accurate, Updated Sales Tax Calculations

No more building tax tables and dealing with ever-changing sales tax rates in thousands of sales tax districts. Get precise sales tax rates & calculations at the state, county, city and special taxing district level so you charge the customer the right amount of sales tax, every time.

Shipping Taxability

Sales tax is so complicated because every state is different. Some states require that merchants charge sales tax on shipping charges, others don’t. TaxJar’s SmartCalcs API factors this in so you don’t have to.

Multi-State Nexus

More states, more complexity. No matter in how many states you have to charge sales tax, TaxJar has you covered.

Product-Level Taxability

Certain products types, like food or clothing are taxed at a lower rate or even tax exempt in some states. SmartCalcs handles complicated product-level taxability so you never have to worry about customizing sales tax rates.

Automated Reporting

TaxJar Reports is included for all sales tax API transactions. Get jurisdiction-level sales tax reporting in every state to make sales tax tracking and filing simple. Additional fees apply for sellers who want TaxJar Reports for other sales channels like Amazon or eBay.

Sourcing Rules

Some states have “origin-based” sales tax sourcing. Others are “destination-based.” TaxJar’s SmartCalcs API comes handles complicated sales tax sourcing rules so you never have to worry about it.

International Support

SmartCalcs supports not just sales tax in the US, but 30 more countries around the world including VAT in the EU and Canada. We even include support for reduced-rate and super reduced-rate product categories. Need support for other countries? Tell us!

Easy to Use and Developer Friendly

SmartCalcs uses modern, RESTful APIs to save you time and hassle. Implement in minutes, and forget about contracts or set-up fees. Look over our documentation for more info on just how easy it is.

Sandbox Environment

Run automated tests against our API sandbox to perform sales tax calculations and validate unique transaction scenarios. It works great with continuous integration tools to ensure your specs are always passing. Automatically generate live and test API tokens after signing up.

High Performance & Reliability

Our sales tax API clocks in at sub-75ms with 99.99% uptime. Check our status page for the breakdown.

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Common Questions

Feel free to contact us if you can't find the answer to your question. We're happy to help you.

How do I get a SmartCalcs API token if I’m already a TaxJar customer?

If you already have a TaxJar account, click here to go to your TaxJar account page. Scroll to the bottom and look for the section called "API Token". Press the button that says "Generate API Token". Your API token will appear within a few seconds.

Can I use the SmartCalcs API to also file sales tax returns?

While the API doesn’t provide this, the application does. When you set up a TaxJar account to get an API token, you also get access to our full application.

What countries does the SmartCalcs API support?

Today we support the United States, Canada, Australia, and European Union. Stay tuned for New Zealand.

Do you have a sandbox for developers and how can I get my sandbox API token?

Yes. All developers that partner with TaxJar have access to our developer sandbox. You can generate your sandbox API token by navigating to your account and selecting "Sandbox Token" from the menu options. More instructions found here.

How long does it take to implement SmartCalcs API?

It depends on your current system. If you already collect all of the necessary information from your customers, you can be up and running, receiving accurate sales tax calculations, in minutes. Seriously.

Does SmartCalcs API support marketplaces that need to provide sales tax calculations for multiple merchants?

Absolutely - our sales tax API was designed specifically for that.

How can I get my transaction history into TaxJar in order to file my sales tax returns?

The best way to get transaction history into TaxJar is through our API. Just view our Transactions endpoint documentation. The second way is to export your transactions to a CSV format that can be directly imported into TaxJar.

TaxJar Guarantee

SmartCalcs Accuracy Guarantee

Our calculations are over 99% accurate and we offer an accuracy guarantee for all SmartCalcs customers. Learn more about our guarantees

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