- Work in progress
- We're currently making substantial changes to this article; a large amount of information is being added and revised.
- Current information
- This article covers information that changes on a regular basis but is accurate as of October 30, 2014.
What you will learn
- What the current MasterCard assessment rates are
- Alternative names that may be used to refer to a particular rate
What you should read first
Assessments are the fees charged by the card associations, such as Visa and MasterCard
Network Access Brand Usage (NABU)
The Network Access Brand Usage Fee is a fee assessed by MasterCard on each authorization (in the case of a transaction) or each settlement (in the case of a Return.
- Network Access Brand Usage (NABU)
- $0.0195, assessed once per transaction
- MC Network Access Auth Fee (used by Wells Fargo)
- MC Ntwork Access Settlement Fee (used by Wells Fargo) 
MasterCard charges data transmission fees for incoming and outgoing interchange records. The Kilobyte Fee is a fee that is charged per kilobyte of a transaction (or chargeback, etc.).
To calculate the Kilobyte Fee, MasterCard determines the total daily count of kilobytes used for incoming and outgoing interchange records for both credit and debit transactions. After determining the count, the System multiplies it by the rate established by MasterCard.
First Data provides details regarding the Kilobyte Fee to its ISOs in a report called the MD-460, Brand Kilobyte Fee Report. This report lists the count of kilobytes for clearing transactions with their calculated fees and the total kilobyte count and fees. The report includes daily and month-to-date counts and amounts at the merchant, principal, and system level. 
- "Payment Network Pass-Through Fee Schedule," October 2014
- First Data Reference Guide