It is 96 degrees. Your AC just died. You called an HVAC company and they can have a crew out tomorrow. The last thing you want to hear is that you need to pull a permit before they start. But in Florida, you almost always do, and skipping it creates problems that outlast the summer heat.
An HVAC system is not an appliance swap. It involves electrical connections, refrigerant handling, ductwork modifications, and equipment that must meet specific energy efficiency codes. Florida has adopted strict energy codes through the Florida Building Code, and a permit ensures the new system is properly sized, correctly installed, and will not create hazards.
Improper refrigerant handling is an EPA violation. Undersized or oversized equipment causes moisture problems that lead to mold. Incorrect electrical work causes fires. The permit and inspection process exists to prevent all of this.
A mechanical permit for AC replacement typically covers:
Your HVAC contractor pulls the permit, not you. If a company asks you to pull it yourself, that is a sign the contractor is not properly licensed.
The inspection typically happens after installation is complete. The inspector checks that the equipment matches what was permitted, the electrical work is correct, refrigerant lines are properly insulated, and the system is functioning. In most Florida jurisdictions, this is a single inspection.
Some counties allow work to begin before a permit is issued in cases of mechanical failure, as long as the permit is applied for the next business day. Call your local building department or have your contractor check. Do not assume. The rules vary by jurisdiction.
If your AC was replaced without a permit and your home has a fire or a mold problem traced back to the installation, your insurance company will ask for the permit documentation. If it does not exist, they may deny the claim.
When you sell, buyers and their inspectors look for permits on major mechanical work. An unpermitted AC replacement typically requires an after-the-fact permit or disclosure. Neither is a great conversation to have at closing.
Mechanical permits for straight replacement (same location, same system type) are often issued same-day or next-day online in most Florida counties. The inspection is usually scheduled within a few days of the work being complete. The total delay is minimal. A good HVAC company factors this into their schedule without you having to ask.
Ask your HVAC contractor if they are pulling a permit before work starts. A licensed contractor will say yes without hesitation. If they suggest you skip it to save time or money, find someone else. The permit protects you, not them.