Late filings. Any pleading described in
paragraph (a) of this section that is filed late must be accompanied by a motion that shows good cause for the untimely filing, unless the Board has specifically granted an extension of time under
paragraph (f) of this section, or unless a motion for extension is pending before the Board. The motion must be accompanied by an affidavit or sworn statement under
28 U.S.C. 1746. (See appendix IV.) The affidavit or sworn statement must include: the reasons for failing to request an extension before the deadline for the submission, and a specific and detailed description of the circumstances causing the late filing, accompanied by supporting documentation or other evidence. Any response to the timeliness motion may be included in the response to the petition for review or may be filed separately. The response to the timeliness motion will not extend the time provided by
paragraph (e) of this section to respond to the petition. In the absence of a motion, the Board may, in its discretion, determine on the basis of the existing record whether there was good cause for the untimely filing, or it may provide the party that submitted the pleading with an opportunity to show why it should not be dismissed or excluded as untimely.