Different taxation systems have individual sets of tax transaction codes. You need to create internal tax transaction codes and map them to the tax transaction codes of the taxation systems you use. In PortaBilling, taxation for all transactions is defined using internal (unified) tax transaction codes. This allows simplifying taxation management for multiple taxation systems (e.g., if you switch from one taxation system to another). At the end of the billing period, when PortaBilling sends transaction xDRs to taxation systems, it adds the actual tax transaction codes of these taxation systems. Internal tax transaction codes are unique for administrators and resellers. See the Unified codes for tax calculation via external plug-ins chapter for more details.
On this panel, you can create internal tax transaction codes and select/add the corresponding tax transaction codes of taxation plug-ins configured in PortaBilling.
To add a new tax transaction code, click +Add on the Tax transaction codes list panel and fill in the details. To save the tax transaction code details, click Save. To create more tax transaction codes, click Save & Add a copy.
Tax transaction code
Type in the internal tax transaction code (numbers only).
Code description
Type in a short description of the internal tax transaction code.
Add customized taxes
Each tax can be applied individually to the charged amount, with the total tax calculated as the sum of all individual taxes. Alternatively, certain tax rules require applying one tax on top of another (compound tax). Based on this, select how taxes should be calculated:
- Basic – collect taxes, where each tax is applied the same charged amount, and the total tax amounts are summed up.
- Cumulative – collect taxes, where the initial tax uses the charged amount, and each subsequent tax is calculated on the amount that includes the total of all previous taxes.
For this type of tax calculation, the order of defined customized taxes matters. To reorder cumulative taxes, select a specific customized tax using Reorder
and drag it up or down.
Customized tax
Select a previously added customized tax.
% of charge that is subject to
Define a percentage of charge that is subject to tax.
Select the corresponding tax transaction codes of the external plug-ins
You can select/specify the corresponding transaction codes of the taxation plug-ins that you enabled on the Taxation plug-ins panel. For Avalara and GST taxation plug-ins, you can select a default code from a drop-down list or add a new code manually. For the SureTax plug-in, you need to add the plug-in codes manually.

