(a) A petition for reopening to correct an error of fact or law in a decision or post-decision order may be filed at any time, but if a petition for reopening is filed by an interested party, or by BIA on behalf of an interested party, it must be filed within 1 year after the interested party's discovery of the alleged error.

(b) If a petition for reopening to correct an error of fact or law in the original decision is filed before the deadline to file a petition for rehearing has passed, it will be treated as a petition for rehearing.