Form 12b-25 (NT 10-K, NT 10-Q)
Also called NT 10-K, NT 10-Q, notification of late filing.
A notice that a company can't file its 10-K or 10-Q on time. On EDGAR it appears as NT 10-K or NT 10-Q.
The notice is due no later than one business day after the report's deadline. If the company then files within 15 calendar days for a 10-K, or 5 calendar days for a 10-Q, the report counts as filed on time. Source 1
The extra time applies only if the report couldn't be filed without unreasonable effort or expense, and the company has to say why. If the delay is because the auditor can't finish, a statement from the auditor is attached. Source 1