Past Practices: Usually Not an Employer’s Friend

A past practice is a pattern of prior conduct consistently undertaken in recurring situations to the point that it evolves into an understanding between the company and the union that the practice is the appropriate course of action. A past practice can be used to clarify ambiguous language in a contract and can be used by arbitrators when an employer and a union have agreed to arbitration in their collective bargaining agreement.

Factors that are generally applied by arbitrators in determining whether activity qualifies as a past practice includes:

  1. Clarity and consistency of the conduct;
  2. Longevity and repetition of the activity;
  3. Acceptability of the pattern; and
  4. Mutual acknowledgement of the conduct by the parties. 

One way to contract around past practice is by including something called a zipper clause in the contract. In a zipper clause, both parties agree to waive their right to demand bargaining on any issue that is not addressed in the contract. Employers who draft a zipper clause in their agreement with a union need to take care that the clause is very specific or it may be deemed unenforceable by the National Labor Relations Board.

Generally, unions and companies make informal deals or do things a certain way throughout the pendency of a collective bargaining agreement. Unsuspecting companies don’t realize that each time they acquiesce to doing something one way, they are establishing a past practice that will forbid them from deviating from that way in the future.

For example, a company may accept oral notice of grievances within 5 days of the event despite having contract language requiring notice be given in writing within 3 days of the event. When a company later wants to go by the letter of the contract and enforce written notice within 3 days, it can’t because it has been accepting oral notice within 5 days.  These types of things happen all the time and employer’s don’t realize they are establishing a past practice until it is too late.

Matt Austin is a Columbus, Ohio lawyer who owns Austin Legal, LLC, a boutique law firm with offices in central and northeast Ohio that limits its representation to employers dealing with labor, employment, and OSHA matters. Austin Legal’s Concierge Legal Services program is relied upon by companies to remain compliant and competitive. If you have employees, you need Concierge Legal Services. You can call Matt at (614) 285-5342 or email him at