18 CFR § 341.4
Amendments of tariff filings
April 15, 2021
A carrier may file to amend or modify a tariff contained in a tariff filing at any time during the pendency of the filing. Such filing will toll the notice period as provided in §341.2(b) for the original filing, and the filing becomes provisionally effective 31 days from the original filing and, in the absence of Commission action, fully effective 31 days from the date of the filing of amendment or modification.
[Order 780, 78 FR 32098, May 29, 2013]