From In-Portal User Manual

General

This is the form for adding and editing the zone information.

• ID – internal, read-only and unique system ID of the tax zone.
• Zone name – zone name for administrator’s information. It is not shown on the storefront, as all of the tax calculation is done automatically by the system.
• Tax Amount – the amount of taxes for this zone. This is a percentage added to the order subtotal, based on the sum of all extended product prices. The tax calculation does not include the shipping costs.
• Type – this is the type of the tax zone. Zones can be defined by country, by state and by zip code. For country zones, the administrator can select any set from the predefined list of countries. For state zones, the administrator chooses one country, and then he or she can select a set of states in that country. For zip-code (postal code) based zones, the administrator has to select the country, and then select a subset of zip codes from the list. If a specific code is not on the list, it can be added using the field below by pressing “Add location”. The list of zip codes is built on the fly from all zip codes used in any zone across all shipping types (it is not practical to maintain it by the system). Note that a zone cannot be of a mixed type, and if you switch the zone type you will loose the information entered for the previous type (for example, if you entered 5 zip codes for a zip-code based zone, then switch the type to country-based, and then switch back to zip-codes, the 5 entries will be gone).