# Overlapping plots > Overlapping plots are plot polygons that share part of their area with other recorded plots. Beyond small edge effects from GPS error, significant overlaps usually signal mapping errors, duplicate registration, disputed land or fraudulent declarations. Also known as: plot overlaps, polygon overlap, duplicate plots ## Why does it matter? Each [plot of land](/glossary/plot-of-land/) should be counted once. Overlaps inflate total area and apparent production capacity, which can let unverified volumes enter a compliant supply chain. They also point to land disputes relevant to the legality requirement. ## How is it detected? Overlap analysis compares every polygon with every other polygon in the dataset, and ideally across datasets from different buyers or programmes. Useful measures include: - overlap area and percentage of each plot; - whether overlaps are between the same farmer's plots (often duplicates) or different farmers; - clusters of plots overlapping many others. ## How is it resolved? - **Duplicates** from repeated registration are merged, which links to [deduplication](/glossary/deduplication/) of farmer records. - **Boundary errors** from [GPS accuracy](/glossary/gps-accuracy/) are corrected by snapping shared edges or re-mapping. - **Real disputes** are documented and escalated. - **Suspected fraud** is investigated before volumes from those plots are accepted. ## Common pitfalls - Checking overlaps only within one company's data, when the same farmer supplies several buyers. - Deleting one of two overlapping plots without investigation. - Ignoring overlaps with [protected areas](/glossary/protected-areas/) and forest reserves. Cross-dataset overlap detection is one of the pre-competitive checks in Farmer1st's [fraud detection](/services/fraud-detection/) service. ## Frequently asked questions ### What overlap is acceptable? There is no regulatory threshold. Programmes usually tolerate small overlaps along shared boundaries, consistent with GPS accuracy, and investigate larger ones. The tolerance should be documented. ### Why are overlaps a fraud signal? The same land registered under several farmers or suppliers can be used to launder volume: produce from unmapped or non-compliant land is declared against a compliant plot that is already claimed elsewhere. ## Sources - [OGC Simple Feature Access standard](https://www.ogc.org/standards/sfa/) - [Regulation (EU) 2023/1115 (EUDR), EUR-Lex](https://eur-lex.europa.eu/eli/reg/2023/1115/oj/eng)