diff --git a/packages/updatePrescriptionStatus/src/validation/fields.ts b/packages/updatePrescriptionStatus/src/validation/fields.ts
index 75cd83103..594d7179c 100644
--- a/packages/updatePrescriptionStatus/src/validation/fields.ts
+++ b/packages/updatePrescriptionStatus/src/validation/fields.ts
@@ -22,8 +22,8 @@ export function taskFields(task: Task): Array<string> {
     (t: Task) => (t.focus?.identifier?.value ? undefined : "LineItemID"),
     (t: Task) => (t.for?.identifier?.value ? undefined : "PatientNHSNumber"),
     (t: Task) => (t.owner?.identifier?.value ? undefined : "PharmacyODSCode"),
-    (t: Task) => (t.basedOn?.[0].identifier?.value ? undefined : "PrescriptionID"),
-    (t: Task) => (t.businessStatus?.coding?.[0].code ? undefined : "Status"),
+    (t: Task) => (t.basedOn?.[0]?.identifier?.value ? undefined : "PrescriptionID"),
+    (t: Task) => (t.businessStatus?.coding?.[0]?.code ? undefined : "Status"),
     (t: Task) => (t.id ? undefined : "TaskID"),
     (t: Task) => (t.status ? undefined : "TerminalStatus")
   ]
diff --git a/packages/updatePrescriptionStatus/tests/validation/testRequestFieldValidation.test.ts b/packages/updatePrescriptionStatus/tests/validation/testRequestFieldValidation.test.ts
index 0364fc3ee..ca43fd3a5 100644
--- a/packages/updatePrescriptionStatus/tests/validation/testRequestFieldValidation.test.ts
+++ b/packages/updatePrescriptionStatus/tests/validation/testRequestFieldValidation.test.ts
@@ -74,6 +74,14 @@ describe("Unit tests for validation of individual fields", () => {
     {
       missingField: "TaskID",
       operation: (t: Task) => delete t.id
+    },
+    {
+      missingField: "PrescriptionID",
+      operation: (t: Task) => (t.basedOn = [])
+    },
+    {
+      missingField: "Status",
+      operation: (t: Task) => (t.businessStatus = {coding: []})
     }
   ])("When $missingField is missing, should return expected issue.", async ({operation, missingField}) => {
     const task = validTask()