How to disable tax calculation for an entire flow (Sales or Purchases)

• To define a rule for order to cash to disable tax calculations applies to all modules, do the following
• Login with Tax Managers Responsibility.
• Navigate to Tax Configuration >> Tax Rules.
• Query for your tax rule
• Click on "Guided rule entry" next to the "Determine Tax Applicability" rule
• Select the Option 'This rule applies to specific transactions only.'
• Select 'Event Class Category' = 'Tax Event Class'.
• Select 'Event Class' = 'Sales Transaction'.
• Enter the other conditions (if any) for this rule then "Next"
• Set the "Applicable tax" as "Not Applicable".  This is the "outcome" for the conditions above.  In our case it would evaluate that for Sales transactions (Order Management, Receivables, Project Invoices, Contracts, iStore, etc..) if the condition from step 8 occurs then set the outcome to "Not Applicable"
• Click Next till last step and then click Finish to save the changes.
• Modify this slightly as need to create a rule for Procure to Pay.