In Marg ERP Software, the user can enable series wise invoice type i.e. Tax & Retail. 

In order to do the same, please follow the below steps:

• Go to Masters > Marg Setups > Control Room. Press Enter.

• A Control Room window will appear.

• The user will select ‘Search in All’. Press Enter.

• A Controls window will appear in which the user will Search 'Invoice Type'.

• Now click on ‘Accept’.

• An Invoice Type window will appear.

• In ‘Invoice Type Taxable/Retail required in Billing' option, the user will select 'Y'.

• The user will now press Escape key twice .

• Then click on ‘Yes’ to Save changes.

After following the above steps invoice type option will get enabled in the series.