Calculation

More accurate locations for ZIP-only addresses

Sales get sourced to the right jurisdiction, even with limited address data.

When a transaction only has a ZIP code, Zamp has to estimate a location. ZIP codes do not always line up with tax jurisdictions, and the standard center point for a ZIP can fall in the wrong jurisdiction or even the wrong state.

Zamp's tax team identified about 1,400 ZIP codes with this problem and supplied corrected coordinates for each one. Zamp now uses those directly, so these sales are sourced to the right place.

More calculation updates

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  1. Tax calculator in the company appAnswer what-if tax questions yourself, instantly.
  2. 2026 sales tax holidaysHoliday exemptions are applied automatically, so you charge the right amount on the right days.
  3. Nontaxable product tax codesA clear option for items you know are nontaxable, instead of workarounds like gift card codes.
  4. Line item level resale exemptionsNo need to split orders, and shipping tax is distributed correctly across the whole order.

Sales tax that keeps getting better, without more work for you.

Talk to a specialist about your states, your systems and what we take over.

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