@Robert Deland
Many of my investors have purchased non conforming properties in Tampa. Run the risk/reward on it. The nice thing about it is most overlay districts in Tampa allow you to build an ADU accessory dwelling unit in the back. That's the hack. Call the city zoning dept and ask if the parcel is in an ADU eligible zone.
If it burns down or a hurricane crushes it, you lose your triplex and you rebuild as a SFR with an ADU. You go from 3 units to 2 units. Again, make sure you are comfortable with the risk/ reward on it and the numbers would work.
Code enforcement tends to be strict in the urban core of Tampa… pulling the correct permits would be in your best interest. As you pull the permits if the job value hits a certain threshold you lose non confirming status and you have an illegal 3 unit.
Your fastest and most efficient solution right now is to extend the contract with an addendum that the seller must receive a “formal decision” with corrected zoning status thru Accela (Tampa online portal) prior to closing. If your current seller can show that the property was leased consistently and has the lease documents, the city might not ask for the architectural drawings in order to sign off on this property to be rezoned. It is a case by case. This process will take at least 60 days and not more than 90 days.
Lastly, if you are using a real estate agent that invests themselves, they should be educating you on this whole process as this is a common yet solvable situation.