diff --git a/README.md b/README.md
index 09b4fc1..e0f8207 100644
--- a/README.md
+++ b/README.md
@@ -46,6 +46,10 @@ The client exposes four resource groups — all endpoints, parameters, and DTOs
 | `client.environments` | `list()`, `get()`, `create()`, `delete()`, `create_entry()`, `delete_entry()` |
 | `client.calculations` | `daily_values()`, `extrapolations()` |
 
+Starting with version 3.0.0, meter-reading CSV exports default to semicolon (`;`).
+To preserve the comma-separated output of version 2.x, explicitly set
+`delimiter=CsvDelimiter.COMMA` in `ExportMeterReadingsDto`.
+
 ## Configuration
 
 ```python
diff --git a/contracts/README.md b/contracts/README.md
index 963626d..1896390 100644
--- a/contracts/README.md
+++ b/contracts/README.md
@@ -18,6 +18,8 @@ test and release checks. No API token, live backend or sibling checkout is neede
   header names case-insensitively; additional transport headers are allowed.
   Query key order and JSON object key order are irrelevant; extra query/body
   fields and duplicate query keys are not allowed.
+- Meter-reading CSV exports default to `semicolon`. Explicit `comma`, `semicolon`
+  and `tab` selections override the default.
 - `response` is the local server's synthetic HTTP response. Bodies use exactly
   one of `json`, UTF-8 `text`, or `base64`; `{}` means no body. A `json: null`
   body is distinct from no body. Base64 preserves exact CSV bytes, including BOM
diff --git a/contracts/cases/errors.json b/contracts/cases/errors.json
index 3eaaf8c..898462b 100644
--- a/contracts/cases/errors.json
+++ b/contracts/cases/errors.json
@@ -194,7 +194,7 @@
         "body": {
           "json": {
             "includeHeader": true,
-            "delimiter": "comma",
+            "delimiter": "semicolon",
             "dateFormat": "iso",
             "columns": [
               "date",
@@ -1285,7 +1285,7 @@
         "body": {
           "json": {
             "includeHeader": true,
-            "delimiter": "comma",
+            "delimiter": "semicolon",
             "dateFormat": "iso",
             "columns": [
               "date",
diff --git a/contracts/cases/meter-readings.json b/contracts/cases/meter-readings.json
index 274a4e3..b2d8c7b 100644
--- a/contracts/cases/meter-readings.json
+++ b/contracts/cases/meter-readings.json
@@ -352,7 +352,7 @@
         "body": {
           "json": {
             "includeHeader": true,
-            "delimiter": "comma",
+            "delimiter": "semicolon",
             "dateFormat": "iso",
             "columns": [
               "date",
@@ -367,12 +367,12 @@
           "Content-Type": "text/csv; charset=utf-8"
         },
         "body": {
-          "base64": "77u/ZGF0ZSx2YWx1ZQ0KMjAyNi0wOS0wMVQxMDozNDo1Ni4xMjNaLDEyMy40NQ0K"
+          "base64": "77u/ZGF0ZTt2YWx1ZQ0KMjAyNi0wOS0wMVQxMDozNDo1Ni4xMjNaOzEyMy40NQ0K"
         }
       },
       "expected": {
         "result": {
-          "base64": "77u/ZGF0ZSx2YWx1ZQ0KMjAyNi0wOS0wMVQxMDozNDo1Ni4xMjNaLDEyMy40NQ0K"
+          "base64": "77u/ZGF0ZTt2YWx1ZQ0KMjAyNi0wOS0wMVQxMDozNDo1Ni4xMjNaOzEyMy40NQ0K"
         }
       }
     },
@@ -462,7 +462,7 @@
         "body": {
           "json": {
             "includeHeader": false,
-            "delimiter": "comma",
+            "delimiter": "semicolon",
             "dateFormat": "iso",
             "columns": [
               "value"
@@ -484,6 +484,102 @@
           "base64": "MTIz"
         }
       }
+    },
+    {
+      "id": "readings-export-explicit-comma",
+      "operation": "meterReadings.export",
+      "input": {
+        "deviceId": "11111111-1111-4111-8111-111111111111",
+        "config": {
+          "columns": [
+            "date",
+            "value"
+          ],
+          "delimiter": "comma"
+        }
+      },
+      "request": {
+        "method": "POST",
+        "path": "/v3/devices/standard/11111111-1111-4111-8111-111111111111/meter-readings/export",
+        "query": {},
+        "headers": {
+          "Authorization": "Bearer contract-test-token",
+          "Content-Type": "application/json"
+        },
+        "body": {
+          "json": {
+            "includeHeader": true,
+            "delimiter": "comma",
+            "dateFormat": "iso",
+            "columns": [
+              "date",
+              "value"
+            ]
+          }
+        }
+      },
+      "response": {
+        "status": 200,
+        "headers": {
+          "Content-Type": "text/csv; charset=utf-8"
+        },
+        "body": {
+          "base64": "77u/ZGF0ZSx2YWx1ZQ0KMjAyNi0wOS0wMVQxMDozNDo1Ni4xMjNaLDEyMy40NQ0K"
+        }
+      },
+      "expected": {
+        "result": {
+          "base64": "77u/ZGF0ZSx2YWx1ZQ0KMjAyNi0wOS0wMVQxMDozNDo1Ni4xMjNaLDEyMy40NQ0K"
+        }
+      }
+    },
+    {
+      "id": "readings-export-explicit-tab",
+      "operation": "meterReadings.export",
+      "input": {
+        "deviceId": "11111111-1111-4111-8111-111111111111",
+        "config": {
+          "columns": [
+            "date",
+            "value"
+          ],
+          "delimiter": "tab"
+        }
+      },
+      "request": {
+        "method": "POST",
+        "path": "/v3/devices/standard/11111111-1111-4111-8111-111111111111/meter-readings/export",
+        "query": {},
+        "headers": {
+          "Authorization": "Bearer contract-test-token",
+          "Content-Type": "application/json"
+        },
+        "body": {
+          "json": {
+            "includeHeader": true,
+            "delimiter": "tab",
+            "dateFormat": "iso",
+            "columns": [
+              "date",
+              "value"
+            ]
+          }
+        }
+      },
+      "response": {
+        "status": 200,
+        "headers": {
+          "Content-Type": "text/csv; charset=utf-8"
+        },
+        "body": {
+          "base64": "77u/ZGF0ZQl2YWx1ZQ0KMjAyNi0wOS0wMVQxMDozNDo1Ni4xMjNaCTEyMy40NQ0K"
+        }
+      },
+      "expected": {
+        "result": {
+          "base64": "77u/ZGF0ZQl2YWx1ZQ0KMjAyNi0wOS0wMVQxMDozNDo1Ni4xMjNaCTEyMy40NQ0K"
+        }
+      }
     }
   ]
 }
diff --git a/energy_tracker_api/models/meter_readings.py b/energy_tracker_api/models/meter_readings.py
index 51a7fb8..55d850a 100644
--- a/energy_tracker_api/models/meter_readings.py
+++ b/energy_tracker_api/models/meter_readings.py
@@ -113,13 +113,13 @@ class ExportMeterReadingsDto:
     Attributes:
         columns: Columns and their order in the exported CSV file.
         include_header: Whether to include the header row (default: True).
-        delimiter: CSV delimiter (default: comma).
+        delimiter: CSV delimiter (default: semicolon).
         date_format: Date format in the export (default: iso).
     """
 
     columns: list[ExportColumn]
     include_header: bool = True
-    delimiter: CsvDelimiter = CsvDelimiter.COMMA
+    delimiter: CsvDelimiter = CsvDelimiter.SEMICOLON
     date_format: DateFormat = DateFormat.ISO
 
     def _to_dict(self) -> dict:
diff --git a/pyproject.toml b/pyproject.toml
index d9f8c96..d07f16d 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "energy-tracker-api"
-version = "2.1.0"
+version = "3.0.0"
 description = "Async Python client for Energy Tracker API"
 readme = "README.md"
 requires-python = ">=3.14"
diff --git a/tests/test_models.py b/tests/test_models.py
index 2104c82..399291b 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -226,7 +226,7 @@ def test_to_dict_with_defaults(self):
         assert result == {
             "columns": ["date", "value"],
             "includeHeader": True,
-            "delimiter": "comma",
+            "delimiter": "semicolon",
             "dateFormat": "iso",
         }
 
@@ -235,7 +235,7 @@ def test_to_dict_with_custom_options(self):
         dto = ExportMeterReadingsDto(
             columns=[ExportColumn.DATE, ExportColumn.VALUE, ExportColumn.NOTE],
             include_header=False,
-            delimiter=CsvDelimiter.SEMICOLON,
+            delimiter=CsvDelimiter.COMMA,
             date_format=DateFormat.UNIX,
         )
 
@@ -246,7 +246,7 @@ def test_to_dict_with_custom_options(self):
         assert result == {
             "columns": ["date", "value", "note"],
             "includeHeader": False,
-            "delimiter": "semicolon",
+            "delimiter": "comma",
             "dateFormat": "unix",
         }
 
diff --git a/tests/test_resources.py b/tests/test_resources.py
index b47dc78..cbf5dc5 100644
--- a/tests/test_resources.py
+++ b/tests/test_resources.py
@@ -369,7 +369,7 @@ class TestMeterReadingResourceExport:
     async def test_export_minimal(self):
         # Arrange
         client = Mock(spec=EnergyTrackerClient)
-        client._make_request = AsyncMock(return_value=b"date,value\n2024-01-15,123.45\n")
+        client._make_request = AsyncMock(return_value=b"date;value\n2024-01-15;123.45\n")
         resource = MeterReadingResource(client)
         config = ExportMeterReadingsDto(columns=[ExportColumn.DATE, ExportColumn.VALUE])
 
@@ -377,7 +377,7 @@ async def test_export_minimal(self):
         result = await resource.export(device_id="device-123", export_config=config)
 
         # Assert
-        assert result == b"date,value\n2024-01-15,123.45\n"
+        assert result == b"date;value\n2024-01-15;123.45\n"
         client._make_request.assert_called_once_with(
             method="POST",
             endpoint="/v3/devices/standard/device-123/meter-readings/export",
@@ -385,7 +385,7 @@ async def test_export_minimal(self):
             json={
                 "columns": ["date", "value"],
                 "includeHeader": True,
-                "delimiter": "comma",
+                "delimiter": "semicolon",
                 "dateFormat": "iso",
             },
             params=None,
@@ -417,7 +417,7 @@ async def test_export_with_filters(self):
             json={
                 "columns": ["date", "value"],
                 "includeHeader": True,
-                "delimiter": "comma",
+                "delimiter": "semicolon",
                 "dateFormat": "iso",
             },
             params={