"Total taxable amount of fees attributable to this tx_id, including amounts associated with MATTER_DISC_CRED where disc_cred_category = ""Fee"". Using the Math Statement on the next tab: The total for pre-split fee items for this tx_id + The total for post-split fee items for this tx_id tax_total_detail_fees If tx_id is a Tiered Tax, the value in this field should be 0. Certain taxes are calculated not only on line items, but also include another tax for these line items -- a ""tax on tax"" situation. For example, in Canada both Quebec and Prince Edward Island have specific taxes calculated on the sum of the line items plus the federal tax paid on those line items. In situations like this, the tax_total_detail_fees figure should include the other tax attributable to the line items so that the math statement for total_tax_on_fees is correct. "