# Understanding the Updated US Tax Calculation in ARTERNAL

Learn how ARTERNAL now calculates precise US tax rates using full address lookup and a clearer tax breakdown on invoices.

Written by Kalila Richards  
December 2, 2025

## **🆕 What’s New?**

ARTERNAL now provides more accurate and transparent tax calculation for US-based invoices. With enhanced address lookup and a redesigned breakdown panel, you can confidently apply the correct sales tax every time.

## **1\. More Accurate Tax Rates with Full Address Lookup**

We upgraded our TaxJar integration so ARTERNAL now calculates tax using the **full shipping address**, not just a ZIP code.

This gives you:

- More precise rates
- Automatic detection of state, county, city, and special district taxes
- Improved compliance with up-to-date local tax laws

📍 _This applies to all invoices with a US shipping address._

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## **2\. A Redesigned Tax Breakdown Panel**

You’ll now see a clear, itemized breakdown of the applied tax rate, including:

- **State tax**
- **County tax**
- **City tax** (when applicable)
- **Special district tax**
- **Combined total tax rate**

This helps you understand exactly how the rate was calculated.

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## **Viewing the Tax Breakdown on an Invoice**

ARTERNAL will automatically suggest the tax rate after you enter the shipping address.

## **To view the full breakdown:**

1. Enter or confirm the **Shipping Address** on your invoice.
2. Look for the banner showing the **calculated tax rate**.
3. Click **See breakdown**.
4. A panel will open showing the full jurisdiction details and tax components.

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## **Adding or Editing Tax Rates Manually**

You can still manually overwrite or add a tax rate if needed.

## **To modify tax on an invoice:**

1. Scroll to the **Tax** section.
2. Adjust the **Rate** or change the **Label** if necessary.
3. Switch between **Percentage** or **Amount**.
4. Click **\+ Additional tax rate** to layer additional tax lines.

## **Frequently Asked Questions:**

**Q. Why is my tax rate different from what I expected?**  
A. Because ARTERNAL now uses full address lookup, city- or district-level taxes may apply even if the ZIP code alone wouldn’t reflect them.

**Q. Does this update affect international invoices?**  
A. No — the enhanced lookup applies only to invoices shipping within the US.

**Q. Why do some addresses show city tax and others don’t?**  
A. City taxes vary by jurisdiction. TaxJar will only include a city tax if the location requires it.

**Q. Can I override the automatically calculated tax?**  
A. Yes, you can adjust the tax line manually at any time. Just click the dropdown, and you can select from a preset tax rate or add a new one.