In most states with lien laws, filing a preliminary notice isn't optional if you want lien rights to mean anything. It has to go out within a fixed window — often 20 days from first furnishing labor or material — and it's a notice, not a threat: it just puts the owner on record that this party could file a lien if payment doesn't happen.
Miss the window and the consequence is specific: lien rights either don't apply at all, or only cover work done in the 20 days before the late notice was sent — everything furnished before that is unprotected.
Example
A material supplier delivers lumber to a jobsite on day one of a project. To preserve lien rights on that delivery, they file a preliminary notice with the county recorder within 20 days — a routine filing that costs little but protects the full value of what they supplied if payment later falls through.
Where this goes wrong on real jobs
The notice window is unforgiving — miss it and the lien right it was meant to protect is gone regardless of how legitimate the unpaid balance is.
“Failing to send a preliminary notice could result in losing your lien rights entirely.”