Four numbers govern NLRB procedure, each with a look-alike. Learn the number with the thing it attaches to.
Six months to file a charge
Section 10(b) bars any complaint based on conduct occurring more than six months before the charge is filed and served. Conduct on March 1 means the charge must be filed and served by September 1.
There is no three-month period in the Act. Twelve months is the Section 9(c)(3) election bar, not the charge limit, and late discovery does not remove the limit.
30 percent showing of interest
An RC (certification) or RD (decertification) petition needs a showing of interest from at least 30 percent of the proposed unit, under Board policy at 29 CFR 101.18. Section 9(e)(1) sets the same 30 percent by statute for union-security deauthorization (UD) petitions.
Work it: a proposed unit of 240 employees needs 240 x 0.30 = 72.
- 121 is a bare majority, which is the vote needed to win the election, not to file the petition. That swap is the most common error.
- 48 is 20 percent and 24 is 10 percent; the Board uses neither.
The 12-month election bar and its 60-day window
Section 9(c)(3) bars an election in a unit where a valid election was held in the preceding 12 months. The Board will accept a petition filed not more than 60 days before that period ends, but the election itself waits until the 12 months expire.
Six months halves the bar, there is no three-year bar, and early filing is allowed, so "only after the period ends" is wrong.
30 days, and 7 in construction
A lawful union-security agreement's grace period before membership may be required cannot be less than 30 days, except that Section 8(f) permits 7 full days in the building and construction industry.
Do not reverse them: 30 at the plant, 7 on the construction project. The exception is real, so "30 in both settings" is wrong, and 60 days is the Section 8(d) contract-notice period, not a grace period.
Carry this in: 6 months charge, 30 percent petition, 12-month bar with 60-day filing, 30 days grace and 7 in construction.