From the SAP Business One Main Menu, choose  Administration Setup Financials Tax Tax Code Determination .

Select either the Service Item or Service Document determination type.

Select values for the Key Field 1,2,3 fields.

For more information, see Tax Code Determination - Setup Window.

Select one row and choose the Key Field Value button.

The Key Field Value - Setup window appears.

For more information, see Key Fields Value - Setup Window.

Specify key field values.

Select one row and choose the Valid Period button.

The Valid Period - Setup window appears.

For more information, see Valid Period - Setup Window.

Specify valid periods.

To save your changes, choose the OK button, and then the Update button.