Union elections are typically held in person, but the labor board determined that the election should be conducted by mail to minimize risks during the pandemic. The ballots were sent to workers in early February and were due at the agency before March 30. Since then, Amazon and the union have had a chance to challenge whether particular workers were eligible to vote.
When the public counting is done, the agency will announce the formal results if the margin of victory for one side is greater than the number of contested ballots.
If the margin is narrower, then it could take two to three weeks for the N.L.R.B. to hold a hearing to sort through the contested ballots and take evidence from both sides on whether they should be counted.
Article source: https://www.nytimes.com/2021/04/08/technology/amazon-union-vote.html