Severity: Error. The Information System rejects the file, or silently stores something other than what you meant.
Fixed automatically?: Yes, after you have seen the change in hectares and accepted it.
In short: Remove the doubled-back section. We show the change in hectares before applying anything.

What the Information System does

It rejects the plot. "Overlapping sides" is the second item on the Commission's list: "Internal overlap or holes where part of the polygon folds inward … are not accepted by the system" (GeoJSON File Description, Common errors 2). We separate this narrower fold-back case from true crossings (Our own check, not an Information System rule).

Why it happens

A fold is a boundary that goes out and comes back along the same line: a spike, or a corridor with no width. It is not a crossing in the usual sense, because the two sides touch rather than pass through each other, but it makes the shape just as invalid.

It is common in boundaries walked with a GPS: the walker goes to a corner post, turns round, and walks back the same way. It also appears when a vertex is dragged onto its neighbour's line while editing.

A broken example

{
  "type": "FeatureCollection",
  "features": [
    {
      "type": "Feature",
      "properties": {
        "ProducerCountry": "CI",
        "ProductionPlace": "Spike",
        "Area": 1.2
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [-5.123456, 6.123456],
            [-5.122456, 6.123456],
            [-5.121456, 6.123456],
            [-5.122456, 6.123456],
            [-5.122456, 6.124456],
            [-5.123456, 6.124456],
            [-5.123456, 6.123456]
          ]
        ]
      }
    }
  ]
}

What the checker reports for this file:

This polygon folds back on itself at point 3: two sides lie on top of each other., line 23, column 13
This polygon folds back on itself at point 4: two sides lie on top of each other., line 27, column 13
This polygon folds back on itself at point 4: two sides lie on top of each other., line 27, column 13

Before. Numbered circles mark where the checker located the problem. Centred on 6.1240° N, 5.1225° W.

Fix it in EUDRplot

Open the file in the checker. The point where the boundary turns back is marked on the map.
Review the repair. Choose Remove the fold. The point where the boundary doubles back is deleted, and the plot's area before and after is shown.
Accept it. Choose Accept the change and apply if the area is right. Changes beyond 2% are refused.

Fix it in QGIS

Find the fold. Run Check validity from the Processing Toolbox. The error output marks the location.
Delete the spike. In edit mode, use the Vertex Tool to select the vertex at the tip of the spike and delete it.
Or repair automatically. Run Fix geometries. Compare the area before and after with $area / 10000.

Try it: check the example, or your own file

Drop a GeoJSON, KML, shapefile or CSV here, or .

Open the full checker

Checked in your browser. The file is not uploaded, stored or sent anywhere.

Sources

EUDR GeoJSON File Description (EUDR Information System help, updated 17 August 2026), Common errors 2, European Commission
Our own check, not an Information System rule, recorded as A6 in our specification notes

Rule GEOM-004, rule set 2026.09.2. The same rule runs in the checker, the free tools and the command-line tool.

Last verified against these sources on 23 September 2026.