First: take a breath. You are not the first contractor, supplier, or project team to discover notice requirements after a project is already underway.
Depending on the state, project type, timing, and your role in the payment chain, missing an early notice deadline may change available payment protection options—but it does not automatically mean every option has disappeared.
In some jurisdictions, late notice may still preserve limited rights moving forward. In others, available remedies may be narrower. Public and bonded projects can also follow entirely different rules.
This is why early project intake matters so much—but it is also why asking the question sooner rather than later is important.
The earlier a situation is evaluated, the more flexibility may exist.
The takeaway?
Discovering the issue late is not ideal.
Assuming there is nothing left to do without evaluating the project details may be worse.