diff --git a/core/src/main/java/org/fao/geonet/kernel/AbstractSchematronValidator.java b/core/src/main/java/org/fao/geonet/kernel/AbstractSchematronValidator.java
index 86454a7a0f2b..3f8ed268f3a5 100644
--- a/core/src/main/java/org/fao/geonet/kernel/AbstractSchematronValidator.java
+++ b/core/src/main/java/org/fao/geonet/kernel/AbstractSchematronValidator.java
@@ -70,6 +70,7 @@ protected void runSchematron(String lang, Path schemaDir, List<MetadataValidatio
             params.put("lang", lang);
             params.put("rule", ruleId);
             params.put("thesaurusDir", thesaurusManager.getThesauriDirectory().toString());
+            params.put("metadataId", metadataId);
 
             Path file = schemaDir.resolve(SCHEMATRON_DIR).resolve(schematron.getFile());
             Element xmlReport = Xml.transform(md, file, params);
diff --git a/core/src/main/java/org/fao/geonet/kernel/SchematronValidatorExternalMd.java b/core/src/main/java/org/fao/geonet/kernel/SchematronValidatorExternalMd.java
index 3f186f05a483..136d692e5113 100644
--- a/core/src/main/java/org/fao/geonet/kernel/SchematronValidatorExternalMd.java
+++ b/core/src/main/java/org/fao/geonet/kernel/SchematronValidatorExternalMd.java
@@ -57,6 +57,9 @@ public Element applyCustomSchematronRules(String schema, Element md,
             List<ApplicableSchematron> applicableSchematron = getApplicableSchematronList(md, metadataSchema, groupOwnerId);
 
             for (ApplicableSchematron applicable : applicableSchematron) {
+                // Pass -1 as metadataId for external validation since the metadata is not in the database.
+                // Schematron rules can reference the metadataId parameter, but attempting to look up metadata
+                // using -1 will return empty results.
                 runSchematron(lang, schemaDir, validations, schemaTronXmlOut, -1, md, applicable);
             }
         } catch (Throwable e) {
diff --git a/core/src/test/java/org/fao/geonet/kernel/AbstractSchematronValidatorTest.java b/core/src/test/java/org/fao/geonet/kernel/AbstractSchematronValidatorTest.java
index c7242793b602..15519e870ca9 100644
--- a/core/src/test/java/org/fao/geonet/kernel/AbstractSchematronValidatorTest.java
+++ b/core/src/test/java/org/fao/geonet/kernel/AbstractSchematronValidatorTest.java
@@ -37,6 +37,7 @@
 import org.fao.geonet.exceptions.ResourceNotFoundEx;
 import org.fao.geonet.utils.Xml;
 import org.jdom.Element;
+import org.mockito.ArgumentCaptor;
 import org.mockito.MockedStatic;
 import org.mockito.Mockito;
 
@@ -44,8 +45,10 @@
 import org.springframework.context.ConfigurableApplicationContext;
 
 import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 import java.util.ResourceBundle;
 
 import static org.junit.Assert.assertEquals;
@@ -127,4 +130,51 @@ public void testRunSchematronLocalizedExceptionHandling() {
             assertEquals(MetadataValidationStatus.NEVER_CALCULATED, validations.get(0).getStatus());
         }
     }
+
+    @Test
+    public void testRunSchematronPassesMetadataIdParam() throws Exception {
+        ConfigurableApplicationContext mockContext = Mockito.mock(ConfigurableApplicationContext.class);
+        try (MockedStatic<ApplicationContextHolder> mockedHolder = Mockito.mockStatic(ApplicationContextHolder.class);
+             MockedStatic<Xml> mockedXml = Mockito.mockStatic(Xml.class)) {
+
+            mockedHolder.when(ApplicationContextHolder::get).thenReturn(mockContext);
+            ThesaurusManager mockThesaurusManager = Mockito.mock(ThesaurusManager.class);
+            Mockito.when(mockContext.getBean(ThesaurusManager.class)).thenReturn(mockThesaurusManager);
+
+            Path thesaurusDir = Paths.get("/thesaurus");
+            Mockito.when(mockThesaurusManager.getThesauriDirectory()).thenReturn(thesaurusDir);
+
+            // Capture the params passed to Xml.transform
+            @SuppressWarnings("unchecked")
+            ArgumentCaptor<Map<String, Object>> paramsCaptor = ArgumentCaptor.forClass(Map.class);
+            mockedXml.when(() -> Xml.transform(Mockito.any(), Mockito.any(Path.class), paramsCaptor.capture()))
+                .thenReturn(new Element("output"));
+
+            AbstractSchematronValidator validator = new AbstractSchematronValidator();
+            int expectedMetadataId = 42;
+            Path schemaDir = Mockito.mock(Path.class);
+            Path schematronFile = Mockito.mock(Path.class);
+            Mockito.when(schemaDir.resolve(Mockito.anyString())).thenReturn(schematronFile);
+            Mockito.when(schematronFile.resolve(Mockito.anyString())).thenReturn(schematronFile);
+
+            List<MetadataValidation> validations = new ArrayList<>();
+            Element schemaTronXmlOut = new Element("schemaTronXmlOut");
+            Element md = new Element("metadata");
+            ApplicableSchematron applicable = Mockito.mock(ApplicableSchematron.class);
+
+            Schematron schematron = new Schematron();
+            schematron.setSchemaName("testSchemaName");
+            schematron.setFile("schematron-rules-test.xsl");
+
+            Mockito.when(applicable.getSchematron()).thenReturn(schematron);
+            Mockito.when(applicable.getRequirement()).thenReturn(SchematronRequirement.REQUIRED);
+
+            validator.runSchematron("eng", schemaDir, validations, schemaTronXmlOut, expectedMetadataId, md, applicable);
+
+            Map<String, Object> capturedParams = paramsCaptor.getValue();
+            assertNotNull("params map should not be null", capturedParams);
+            assertEquals("metadataId should be passed to the schematron XSL transform",
+                expectedMetadataId, capturedParams.get("metadataId"));
+        }
+    }
 }
diff --git a/docs/manual/docs/customizing-application/implementing-a-schema-plugin.md b/docs/manual/docs/customizing-application/implementing-a-schema-plugin.md
index ba14664fa6bb..3023734c47ca 100644
--- a/docs/manual/docs/customizing-application/implementing-a-schema-plugin.md
+++ b/docs/manual/docs/customizing-application/implementing-a-schema-plugin.md
@@ -1220,6 +1220,17 @@ As for most of GeoNetwork, the output of this rule can be localized to different
 </strings>
 ```
 
+##### Available parameters in schematron rules
+
+When GeoNetwork executes a compiled schematron, the following parameters are automatically passed to the XSL and can be referenced inside `<sch:rule>` blocks using `$paramName`:
+
+| Parameter       | Type    | Description                                                                 |
+|-----------------|---------|-----------------------------------------------------------------------------|
+| `lang`          | string  | The two or three letter language code of the current user session (e.g. `eng`). Use this to return localised messages. |
+| `rule`          | string  | The file name of the compiled schematron XSL (e.g. `schematron-rules-iso.xsl`). |
+| `thesaurusDir`  | string  | Absolute path to the GeoNetwork thesaurus directory. Useful for rules that need to validate against controlled vocabularies. |
+| `metadataId`    | integer | The internal database identifier of the metadata record being validated. Useful for rules that need to look up related information. **Note:** When validating external metadata (metadata not saved to the database), this parameter is set to `-1`. Attempts to query the database using this value will return empty results. |
+
 Procedure for adding schematron rules, working within the schematrons directory:
 
 1.  Place your schematron rules in 'rules'. Naming convention is 'schematron-rules-<suffix>.sch' eg. `schematron-rules-iso-mcp.sch`. Place localized strings for the rule assertions into 'rules/loc/<language_prefix>'.
diff --git a/web/src/main/webapp/WEB-INF/classes/schematron/iso_svrl_for_xslt2.xsl b/web/src/main/webapp/WEB-INF/classes/schematron/iso_svrl_for_xslt2.xsl
index 5ddd944219da..34d8280ac2ba 100644
--- a/web/src/main/webapp/WEB-INF/classes/schematron/iso_svrl_for_xslt2.xsl
+++ b/web/src/main/webapp/WEB-INF/classes/schematron/iso_svrl_for_xslt2.xsl
@@ -210,6 +210,7 @@
     <axsl:param name="lang"/>
     <axsl:param name="thesaurusDir"/>
     <axsl:param name="rule"/>
+    <axsl:param name="metadataId"/>
 
     <!-- Retrieve localisation entries (one file specific to the rule, the other file is shared by all schematron). Fallback language is English. -->
     <axsl:variable name="loc">
diff --git a/web/src/test/java/org/fao/geonet/kernel/schema/AbstractSchematronTest.java b/web/src/test/java/org/fao/geonet/kernel/schema/AbstractSchematronTest.java
index e44e5a030897..372020fd5f92 100644
--- a/web/src/test/java/org/fao/geonet/kernel/schema/AbstractSchematronTest.java
+++ b/web/src/test/java/org/fao/geonet/kernel/schema/AbstractSchematronTest.java
@@ -115,6 +115,7 @@ protected Pair<Element, Path> compileSchematron(Path sourceFile) {
             params.put("lang", "eng");
             params.put("thesaurusDir", THESAURUS_DIR.toAbsolutePath().toString().replace("\\", "/"));
             params.put("rule", ruleName + ".xsl");
+            params.put("metadataId", "0");
 
             Path outputFile = temporaryFolder.getRoot().toPath().resolve("path/requiredtoFind/utilsfile/" + ruleName + ".xsl");
             Files.createDirectories(outputFile.getParent());