What it is
Under Fla. Stat. 627.70152, before you can sue a residential or commercial property insurer in Florida you must first file a written notice of intent to initiate litigation with the Department of Financial Services (DFS). You do not serve the carrier yourself; DFS forwards the notice to the insurer's designated address. The notice has to include a presuit settlement demand that itemizes the damages, attorney fees, and costs, and it must be given at least 10 business days before you file suit. It is a condition precedent, not optional paperwork.
The presuit timeline
Once the notice lands, the insurer must respond in writing within 10 business days. If the notice alleges a coverage denial, the carrier may accept coverage, keep denying, or assert a right to reinspect the property (14 business days to do so after that response). For any other dispute, such as an underpayment, the insurer must make a settlement offer or require appraisal or another form of alternative dispute resolution. If it routes you into appraisal or ADR and that process is not concluded within 90 days after the 10-day notice period expires, you may file suit without giving further notice.
What happens if you skip it
The consequence is blunt: a court must dismiss without prejudice any suit filed without the required notice. "Without prejudice" means you are not permanently barred, but you have to go back, serve the notice, wait out the timeline, and start over while your filing deadline keeps running. Treat the notice as the first step of litigation strategy, not an afterthought. A narrow 30-day tolling exists at the tail end if the limitations period would otherwise expire during the process, but it is too thin to rely on.