Union “security agreements” can require all employees, as a condition of employment, to pay a “fair share” or representational costs. This is sometimes miscast as requiring union “membership”; the NLRB has ruled that unions have an affirmative duty to inform employees that membership is not required. This article discusses the permissible uses for union dues, how such dues can be challenged by employees, arbitration of discharges for non-payment of dues, and the AAA “fair-share” determination process. A right-to-work attorney asserts that the AAA “fair-share” determination process is, itself, unfair, and an NEA attorney asserts that it is not.