This article outlines the database structure for the MMv4 tax database table.

• id
  Primary Key of the table.
  int(10) | unsigned | auto increment | primary key | indexed
  
• name
  The name of the tax. This name is displayed in the storefront to customers.
  varchar(255) | indexed
  
• active
  If this field contains a value greater than zero, then the tax is active. Only active tax rules are applied to customer orders.
  int(10) | Values: 0/timestamp | Default: 1 | indexed
• and_or
  Determines whether all or any of tax's zones must match the customer's geographic location.
  For example, if a tax uses the zones California and United States, a tax set to "and" would be applied to customers with California selected as their state and United States selected as their country. If set to "or", then the tax would be applied to customers with either California selected as their state or United States selected as their country.
  char(1) | values: O,A | default: O
• bill_v_ship
  This will specify which customer address the tax will be applied to. B for Billing Address and S for Shipping address.
  char(1) | values: B, S | default: B
  
• use_ship_fee
  Specifies whether the tax will include the shipping charges or not.
  int(10) | Values: 0/timestamp
  
• value
  The value of the tax. The value may represent either a dollar value or percentage, depending of the value of the "type" field. The value field may have up to three decimal places. Example: 1.234.
  double(15,3)
  
• type
  If set to "P", then the tax is calculated as a percentage. If set to "D", then the tax is calculated as a dollar value.
  char(1) | values: P,D | default: P
  
• notes
  Internal notes about the tax. These notes are displayed only within the store's administration area.
  text