diff --git a/doc/release_notes.rst b/doc/release_notes.rst
index e017b07d..e6441cad 100644
--- a/doc/release_notes.rst
+++ b/doc/release_notes.rst
@@ -10,6 +10,11 @@ Release Notes
 Upcoming Release
 ================
 
+* Regions are assigned to all buses with unique coordinates in the network with
+  a preference given to substations. Previously, only substations had assigned
+  regions, but this could lead to issues when a high spatial resolution was
+  applied.
+
 * The default configuration ``config/config.default.yaml`` is now automatically
   used as a base configuration file and no longer copied to
   ``config/config.yaml`` on first use. The file ``config/config.yaml`` should be
diff --git a/scripts/base_network.py b/scripts/base_network.py
index 2bfee9d7..81db4074 100644
--- a/scripts/base_network.py
+++ b/scripts/base_network.py
@@ -559,6 +559,7 @@ def _set_countries_and_substations(n, config, country_shapes, offshore_shapes):
     for b, df in product(("bus0", "bus1"), (n.lines, n.links)):
         has_connections_b |= ~df.groupby(b).under_construction.min()
 
+    buses["onshore_bus"] = onshore_b
     buses["substation_lv"] = (
         lv_b & onshore_b & (~buses["under_construction"]) & has_connections_b
     )
diff --git a/scripts/build_bus_regions.py b/scripts/build_bus_regions.py
index a6500bb0..f9bf287e 100644
--- a/scripts/build_bus_regions.py
+++ b/scripts/build_bus_regions.py
@@ -135,7 +135,13 @@ if __name__ == "__main__":
         c_b = n.buses.country == country
 
         onshore_shape = country_shapes[country]
-        onshore_locs = n.buses.loc[c_b & n.buses.substation_lv, ["x", "y"]]
+        onshore_locs = (
+            n.buses.loc[c_b & n.buses.onshore_bus]
+            .sort_values(
+                by="substation_lv", ascending=False
+            )  # preference for substations
+            .drop_duplicates(subset=["x", "y"], keep="first")[["x", "y"]]
+        )
         onshore_regions.append(
             gpd.GeoDataFrame(
                 {
diff --git a/scripts/simplify_network.py b/scripts/simplify_network.py
index 31bc8f4e..cc4ff4f6 100644
--- a/scripts/simplify_network.py
+++ b/scripts/simplify_network.py
@@ -611,6 +611,7 @@ if __name__ == "__main__":
         "symbol",
         "tags",
         "under_construction",
+        "onshore_bus",
         "substation_lv",
         "substation_off",
         "geometry",