Updated: January 16, 2026 2:45pm

Prism Users Guide - Chapter 5. Taxes
5.9 Detax

5.9.1 About Detax
(VAT only)
Detax is the full removal of tax for special groups of customers. Detax updates the transaction total (unlike tax rebates). Detax is typically used with certain customers who are exempt from paying tax (e.g. diplomats).  To use Detax, you must configure Prism preferences to enable the feature. You can configure detax to occur automatically and/or manually. If you want detax to occur automatically, select the Detax flag in the customer record of eligible customers and select the "Zero Out Tax for Detax Customers" option in preferences. 

Detax Use Cases

Use Case Notes
Detax Customer - Manual Detax A customer, marked for Detax, makes a purchase for export.  The transaction is created and manually Detaxed by the cashier.
Detax Customer - Automatic Detax A customer, marked for Detax, makes a purchase for export.  The transaction is created and automatically Detaxed.
Non-Detax Customer - Manual Detax A customer, not marked for Detax, makes a purchase for export.  The transaction is created and manually Detaxed by the cashier.

 

5.9.2 Select Detax Flag in Customer Record
1.    Use Customer Lookup to find and display the customer's record.    
2.    Touch or click the Credit Detail Button.    
3.    Touch or click the Edit button.     
4.    Navigate to the Detax field. Select the check box to designate the customer as a Detax Customer. If selected, and "Zero out tax for Detax customers" is enabled in preferences, transactions listing the customer are eligible for detax.    
5.    Touch or click the Save button.

5.9.3 Configure Manual Detax Permission
If allowing manual detax, make sure the user belongs to a group that is assigned the POS - Allow Manual Detax permission.

 5.9.4 Configure Detax Preferences
Enable Detax and Configure Detax Preferences
The following preferences control to Detax. To access these preferences, go to the Admin Console and select Node Preferences > Taxes > General. Refer to the following table for a description of the preferences.

Preference Description
Zero Out Tax for Detax Customers This preference is only available if the Tax Method is set to VAT (or ICM). If selected, when a customer whose Detax field is selected is added as the Bill To or Ship To customer on a transaction, the Tax $ amount will be removed/set to 0. Use this option if you want the Detax to occur automatically at POS.
Apply Detax to Tax % This option enables manual detax for non-detax customers (or no customer).
Apply Detax to Shipping This option enables users to manually remove tax on shipping (if a tax percentage is assigned for Shipping). 
Apply Detax to Fees

 This option enables users to manually remove tax on fees (if a tax percentage is assigned for the fee). 

Apply Detax [Before or After Discount]

Controls when detax is applied, before or after discounts.
Before Discounts, when Detax flag is enabled:

  • Items are posted with the tax portion of the VAT price removed
  • Discounts are applied against the Detaxed price
  • Detaxed Active Price - Discounts = Detaxed Receipt Price
When Detax flag is disabled: Items are posted with the full VAT price, tax included, discounts are applied to the full VAT price and Taxed Active Price - Discounts = Taxed Receipt Price
Note: As the Detax flag condition changes and the receipt items are reprocessed, the pricing will toggle to the appropriate method. Discounts will process forward from that state.
After Discounts, when Detax flag is enabled:
  • Items are posted with the full VAT price, tax included
  • Discounts are applied to the full VAT price
  • Taxed Active Price - Discounts = Taxed Receipt Price
  • Tax portion of Receipt Price is removed

When Detax flag is disabled: Items are posted with the full VAT price, tax included, iscounts are applied to the full VAT price and Taxed Active Price - Discounts = Taxed Receipt Priced
As the Detax flag condition changes, the tax values will be included or removed.

Sample Detax preferences (Admin Console > Node Preferences > Taxes > General):
detax preferences

5.9.5 Automatic Detax at Point-of-Sale
If the "Zero out tax for Detax customers" preference is selected, then when such a customer is entered on the transaction, the tax is automatically removed. Removing the customer will remove the detax amount (restoring the tax).
Checking Detax Amount on Transaction
To verify the amount of tax removed, go to Transaction Details and select the Taxes tab. Navigate to the bottom of the screen to the Detax Transaction area.
Removing Automatic Detax
If you need to remove an automatic detax, simply remove the customer from the transaction. 

5.9.6 Manual Detax
Users with the required security permission (POS - ALLOW MANUAL DETAX) can manually detax a transaction 
Go into Transaction Details and select the Taxes tab.
Click Detax.
Click OK.

5.9.7 Detax of Fees and Shipping
If you want to detax fees or shipping, you must assign a tax percentage to the fee type or shipping. If the Tax Incl. (Tax Included) flag is selected for a fee type, then whatever value the user enters will be automatically adjusted to include the tax amount in the fee. 
Example (VAT Environment)
Fee has a tax percentage of 10% in preferences. User enters a Fee of 100.00 on transaction
If Tax Incl. flag is selected:
   Fee Tax Amount: 9.09
   Total Fee without Tax: 90.91
   Total Fee with Tax: 100.00
Tax Incl. flag is not selected.
   Fee Tax Amount: 10.00
   Total Fee without Tax: 100.00
   Total Fee with Tax: 110.00

5.9.8 Detax Status of Returned Items
Prism tracks the detax status of individual transaction items. When returning an item that was detaxed, even if the detax customer is changed or removed, the item being returned will retain its orginal detax status. That is, tax was removed when the item was purchased (detaxed). It should not, therefore, be added just because it is being returned (regardless of who the customer is doing the returning).  This prevents tax from being incorrectly applied to return items.