The NLRA imposes additional requirements before a union can invoke a union shop agreement clause to require an employer to fire an employee who has failed to pay dues. While the union does not have to give the individual employee the sort of trial-type hearing required by the LMRDA to expel a union member for other reasons, the union must give the employee a detailed written explanation of the amount of delinquent dues that the employee owes and how those dues were calculated, and allow the employee a reasonable opportunity to pay those delinquent dues and fees before it asks that the employee be fired. In addition, the union must give all employees roughly the same opportunity to cure any delinquencies before requesting discharge; if the union gives one employee two weeks to pay delinquent dues, it must do the same for all others. The union is not, on the other hand, required to withdraw a request that an employee be fired for failure to pay delinquent dues if the employee makes the payment after the deadline but before the employer has effected the discharge. A union may owe back pay to employees who have been fired without these procedural protections; the employer may be liable if it effects the discharge when it knew or should have known that the union had not complied with the minimum requirements of the NLRA.