diff --git a/src/sg/gov/tech/notarise/1.0/notarise-open-attestation-document.json b/src/sg/gov/tech/notarise/1.0/notarise-open-attestation-document.json
index cb250ba..106cfaa 100644
--- a/src/sg/gov/tech/notarise/1.0/notarise-open-attestation-document.json
+++ b/src/sg/gov/tech/notarise/1.0/notarise-open-attestation-document.json
@@ -17,6 +17,7 @@
   "notarisationMetadata": {
     "reference": "967857",
     "notarisedOn": "2020-09-27T06:15:00Z",
-    "passportNumber": "DT173NV"
+    "passportNumber": "DT173NV",
+    "url": "https://example.com"
   }
 }
diff --git a/src/sg/gov/tech/notarise/1.0/sample-document.json b/src/sg/gov/tech/notarise/1.0/sample-document.json
index bd9ae11..ab82078 100644
--- a/src/sg/gov/tech/notarise/1.0/sample-document.json
+++ b/src/sg/gov/tech/notarise/1.0/sample-document.json
@@ -2,6 +2,7 @@
   "notarisationMetadata": {
     "reference": "967857",
     "notarisedOn": "2020-09-27T06:15:00Z",
-    "passportNumber": "DT173NV"
+    "passportNumber": "DT173NV",
+    "url": "https://example.com"
   }
 }
diff --git a/src/sg/gov/tech/notarise/1.0/schema.json b/src/sg/gov/tech/notarise/1.0/schema.json
index 8696ebb..c5e58a0 100644
--- a/src/sg/gov/tech/notarise/1.0/schema.json
+++ b/src/sg/gov/tech/notarise/1.0/schema.json
@@ -20,9 +20,14 @@
         "passportNumber": {
           "description": "Passport number of the recipient",
           "type": "string"
+        },
+        "url": {
+          "description": "URI to the stored document",
+          "type": "string",
+          "format": "uri"
         }
       },
-      "required": ["notarisedOn", "passportNumber", "reference"]
+      "required": ["notarisedOn", "passportNumber", "reference", "url"]
     }
   },
   "required": ["notarisationMetadata"]
diff --git a/src/sg/gov/tech/notarise/1.0/schema.test.ts b/src/sg/gov/tech/notarise/1.0/schema.test.ts
index 93d396c..75f3847 100644
--- a/src/sg/gov/tech/notarise/1.0/schema.test.ts
+++ b/src/sg/gov/tech/notarise/1.0/schema.test.ts
@@ -95,4 +95,38 @@ describe("schema", () => {
       ]
     `);
   });
+  it("should fail when notarisationMetadata url is missing", () => {
+    const isValid = validator(omit(cloneDeep(sampleDocJson), "notarisationMetadata.url"));
+    expect(isValid).toBe(false);
+    expect(validator.errors).toMatchInlineSnapshot(`
+      Array [
+        Object {
+          "dataPath": ".notarisationMetadata",
+          "keyword": "required",
+          "message": "should have required property 'url'",
+          "params": Object {
+            "missingProperty": "url",
+          },
+          "schemaPath": "#/properties/notarisationMetadata/required",
+        },
+      ]
+    `);
+  });
+  it("should fail when notarisationMetadata url is not a URI", () => {
+    const isValid = validator(set(cloneDeep(sampleDocJson), "notarisationMetadata.url", "FOO"));
+    expect(isValid).toBe(false);
+    expect(validator.errors).toMatchInlineSnapshot(`
+      Array [
+        Object {
+          "dataPath": ".notarisationMetadata.url",
+          "keyword": "format",
+          "message": "should match format \\"uri\\"",
+          "params": Object {
+            "format": "uri",
+          },
+          "schemaPath": "#/properties/notarisationMetadata/properties/url/format",
+        },
+      ]
+    `);
+  });
 });