Decimal places: at least 6, and what truncation does to your polygons

EUDR geolocation must use at least 6 decimal places. The EU Information System also cuts anything beyond 6 decimals, which can quietly create duplicate points and invalid shapes.

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What the EU documentation says

• The FAQ defines geolocation as latitude/longitude coordinates "with a minimum of 6 decimal digits". The DDS API reference repeats it: coordinates must have a minimum of 6 decimal digits.
• The GeoJSON File Description says the system truncates coordinate points to 6 decimal places before storing, that sending more is "superfluous/wasteful", and that in extreme cases it may even produce invalid geometries where the original was valid. The Validation Rules say the same.
• Its list of common errors includes "duplicate coordinates due to truncation to 6 decimals", with an example: -5.8227391234, 144.2567071234 and -5.8227394567, 144.2567074567 both become -5.822739, 144.256707.

Too few decimals

A coordinate like -4.02, 5.31 has two decimals: it locates a point only to about a kilometre. Files often lose decimals when a spreadsheet column is formatted to show 2 or 4 places and then saved as CSV, or when a phone app exports rounded values. Re-exporting won't bring the lost precision back; you need the original data or a new GPS reading.

One subtlety: JSON writers drop trailing zeros, so -49.00683 may really be -49.006830. The EU's own sample file contains values like that. A fair test looks at the longest value in a plot, not at every single number.

Too many decimals

Sending 10 or 15 decimals is harmless by itself, but because of truncation two corners that were 0.0000003 degrees apart become the same point. A polygon with repeated corners, or with corners that collapse into a line, can then become invalid. The fix is to truncate to 6 decimals yourself and then remove consecutive duplicate points, so you can check the result before the system does.

What the Plot File Checker does

• Fewer than 6 decimals (judged on the longest value in each plot): an error. The fixed file writes 6 decimals, but the checker still warns about low GPS precision if the data had 4 decimals or fewer, because padding with zeros doesn't add accuracy.
• More than 6 decimals: truncated to 6, as the EU system does. Duplicates this creates are removed and the plot is re-checked for shape problems.
• Repeated consecutive points: a warning, removed in the fixed file.

Good practice

Keep the raw GPS data with full precision in your own records, and produce the upload file from it with exactly 6 decimals. Format spreadsheet coordinate columns as text or with at least 6 decimals so nothing is rounded when saving.