While you might think that the Folio number is just a randomly generated series of numbers, Miami-Dade County actually explains in detail on its website what each digit actually means.
The Folio number is a 13 digit number formatted in this manner: 99-9999-999-9999, with the segments representing a property’s Municipality, Township, Range, Section, Sub-division and Parcel Identifier.
Municipality:
The 1st two digits of the folio number are the municipal code as listed on this adjoining chart. Code 30 indicates properties in Miami-Dade County not within the municipality, otherwise referred to as “unincorporated.”
Township, Range, and Section:
The next 4 digits indicate the, Township, Range and Section based on the Public Land Survey System (PLSS).
Township:
The first digit is the township number. Townships run from North to South in ascending order. Miami-Dade starts with township 51 in the north and changes every 6 miles going South until township 59. The first number of the township (5) is omitted and only the second number is used in the folio number. A township is 36 square miles.
Range:
The second of these 4 is the range number. Range numbers start with range 35 in the extreme West and change every 6 miles going East until range 42. The first digit of the range (3 or 4) is omitted and only the last number is used in the folio number.
Section:
The last two digits are the section number. This could be any number between 1 and 36, there being 36 sections in each township and range grid. A section is normally one square mile.
Sub-Division:
The next 3 digits are the subdivision number, acreage or plat. Un-subdivided properties will show 000 in this portion of the folio number. Every subdivision within a section is given a consecutive number. Therefore, 006 within a section is the 6th subdivision recorded within this section. Some acreage parcels were originally part of old subdivisions and carries 001 or 002 designation under subdivision, even though these are large tracts (acreage).
Parcel Identifier:
The last 4 digits are the actual parcel number.