Receiving a Director Penalty Notice puts your client on a strict 21-day clock...

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

Receiving a Director Penalty Notice puts your client on a strict 21-day clock starting from the issue date. The consequences depend heavily on whether it’s a lockdown or non-lockdown notice