docs/8.0/ayanova/docs/acc-tax-codes.md

@@ -25,7 +25,6 @@ Read only access
 - Sales
 - Sales - restricted
 
-
 ## How to access Tax codes
 
 Tax codes are accessed in the following ways:
@@ -36,16 +35,33 @@ Tax codes are accessed in the following ways:
 
 ## How Tax codes work
 
+### Selecting
+
 Tax codes are selected on [Purchase orders](inv-purchase-orders.md), [Work orders](svc-workorders.md), [Quotes](svc-quotes.md) and [Preventive Maintenance](svc-pms.md) orders to indicate and calculate taxes for both purchase and sales events.
 
+### Locked when used
+
 Tax code Percentages and Tax on Tax fields are **locked** to prevent editing once they are used on another object in order to protect the historical record. Other fields remain editable as they would not affect past record tax calculations.
 
 After an edit and save that affects any of the calculation affecting fields the AyaNova server will check if any objects are using this Tax code and if any are found will prevent the change and report back all object types involved. Options are to remove or switch the Tax code from the existing in-use objects to be able to edit those fields or simply make a new Tax code.
 
-When a tax code is retired it should be set to inactive by un-checking it's Active checkbox and a new active tax code created to take it's place. 
+### Retiring
 
-If a tax has been selected in [Global Settings](adm-global-settings.md#default-parts-purchase-tax) as a default it can not be deleted.
+When a tax rate changes a new tax code must be made to replace the previously used tax code with the now outdated rate in order to preserve historical data. The old rate must be "retired" to prevent it from being used in future.
 
+When a tax code is retired it should be set to inactive by un-checking it's Active checkbox and a new active tax code created to take it's place. Setting to inactive prevents it from being selected on new records but still shows it on historical records.
+
+Due to the need to replace tax codes from time to time and the requirement that Names be unique we recommend tax codes be named uniquely by appending the year they go into effect or some other system that makes sense for your needs.
+
+### Automatic default
+
+Tax codes can be set to default automatically (you can still change the default when necessary) in [Global Settings](adm-global-settings.md#default-parts-purchase-tax).
+
+A default tax code can not be deleted unless it is removed as a default first.
+
+### Not required
+
+Tax codes are optional and not required to be used if they are not appropriate for your situation.
 
 ## Tax codes data table
 
@@ -65,15 +81,20 @@ This is the primary tax field and should be entered as a [percentage](ay-start-d
 
 #### Tax B
 
+The "B" tax is a secondary tax that can also be applied in tax calculations for situations where more than one tax is required to be used.
+
 #### Tax on Tax
 
-Charge to customer per unit for this service. [Currency](ay-start-data-types.md#currency) field. This field is **locked** once the rate is used in AyaNova to preserve historical data.
+Tax On Tax set to checked / true indicates that when totals are calculated, Tax B is applied to the total of the item including the increase due to Tax A.
 
+For example, if you had a tax code that was 5% for Tax A and 6% for Tax B, and the product the tax was applied to was priced at $10.00, Tax A would be $0.50 ($10.00 _ 5%) and Tax B would be $0.63 (($10.00 + $0.50 Tax A) _ 6% Tax B)
+
+If Tax on Tax is not checked / false then each tax is calculated separately and then added to the total.
 
 #### Active
 
-Rates that are set to Active can be selected on new Work orders and other objects that user Tax codes.  
-Rates not set to Active will still show in older records but can not be selected for new records; this is how you retire a rate from use.
+Taxes that are set to Active can be selected on new Work orders and other objects that user Tax codes.  
+Taxes not set to Active will still show in older records but can not be selected for new records; this is how you retire a rate from use.
 
 #### Notes
 
@@ -94,8 +115,3 @@ Standard AyaNova object [wiki control](ay-start-form-wiki.md).
 #### Attached files
 
 Standard AyaNova object [attachments control](ay-start-form-attachments.md).
-
-000000000000000000000000000000000000000000000000000
-Notes to include in docs:
-
-Data integrity - Tax code values are stored only in the Tax Code object and linked to by objects affected by that Tax code (e.g. Work order item labor record).