When a DPN arrives, the 21-day clock starts on the issue date. You must...

https://dlf-ne.org/how-do-i-spot-a-lockdown-dpn-before-the-client-wastes-money-on-the-wrong-step/

When a DPN arrives, the 21-day clock starts on the issue date. You must identify whether it is a lockdown or non-lockdown penalty to determine the best path. Master these distinctions to guide your clients, so you can triage fast and keep options open.