Every place, and how it connects.
Shared across datasets.

Many descriptions, one place

The city of São Paulo shows up in public data in several forms. Brazil's statistics agency, IBGE, gives it municipality code 3550308. A field survey records a coordinate on Avenida Paulista. A spreadsheet just types the name. The code and the coordinate both resolve to the city's loc_id.

The name is the weak input. São Paulo is both a city and the state around it, and the two have different ids. Codes differ between agencies and names repeat, so matching them by hand breaks easily. Resolving them once to a loc_id turns that cleanup into a step you do once and reuse.

Reading a loc_id

Most ids follow a country's administrative spine: the nested chain from country to state, county, and smaller areas. Each segment adds one level. This id is a census block in Fairfax County, Virginia. Select a segment to walk the chain.

Two rules cover the spine. The number of segments gives the level, and dropping the last segment gives the parent. Each segment holds only that level's own code with its leading zeros, so Census block 1011 in block group 1 is written 011.

The same rules hold in every country, with each country's own official codes in the segments. The UK segments are ONS statistical codes, and Brazil's municipality segment is the IBGE code. Level names and depth vary by country.

Deepest level returned by a single coordinate lookup, September 2026. Several of these countries go deeper with a second lookup.

Places that cross the lines

Plenty of useful geography does not fit inside the spine. ZIP code 42223 covers Fort Campbell, the Army post on the Kentucky-Tennessee border, and it crosses the state line.

So the ZIP code keeps its own identity in the postal-area family, and a published crosswalk records how it overlaps the spine. A dataset keyed by ZIP can reach county data in both states through that crosswalk, with the shares visible, instead of being forced into one county.

Postal areas are one of several geometry families that sit beside the spine. Each keeps its own ids and connects through crosswalks.

Rows that share a spine loc_id join directly. Rows from different families connect through a crosswalk, which states the type of relationship and the source it came from.

Places that change

Counties merge and census tracts are redrawn every ten years. A loc_id belongs to the source release it came from, and crosswalks connect older and newer versions of a place with the evidence for each link. Every result reports which release each level is built on.

Some boundaries are disputed. A loc_id says which geography a row describes and makes no claim about who governs it. Coordinates stay where the source put them: DaedalMap reports the area a point falls in and never moves a point to make it fit.

Examples

Ids at different depths and from a geometry family. Spine ids read by segments; the postal-area id is a family id and is read with the geometry tools.

Add loc_ids to your data

Upload a CSV or spreadsheet with coordinates or place codes. DaedalMap identifies the geography, adds a loc_id column to a sample, and lets you download it. The same resolution runs on full files, in the local runtime, and through the MCP tools.