diff --git a/client/src/components/jobs-close-lines/jobs-close-lines.component.jsx b/client/src/components/jobs-close-lines/jobs-close-lines.component.jsx
index f1a1bf3f2..e6bdc5321 100644
--- a/client/src/components/jobs-close-lines/jobs-close-lines.component.jsx
+++ b/client/src/components/jobs-close-lines/jobs-close-lines.component.jsx
@@ -42,6 +42,10 @@ export function JobsCloseLines({ bodyshop, job, jobRO }) {
               <tbody>
                 {fields.map((field, index) => (
                   <tr key={field.key}>
+                    {/* Hidden field to preserve jobline ID */}
+                    <Form.Item hidden name={[field.name, "id"]}>
+                      <input />
+                    </Form.Item>
                     <td>
                       <Form.Item
                         //   label={t("joblines.fields.line_desc")}
diff --git a/client/src/pages/jobs-close/jobs-close.component.jsx b/client/src/pages/jobs-close/jobs-close.component.jsx
index 89ed10fd0..eb09d7d2c 100644
--- a/client/src/pages/jobs-close/jobs-close.component.jsx
+++ b/client/src/pages/jobs-close/jobs-close.component.jsx
@@ -82,10 +82,23 @@ export function JobsCloseComponent({ job, bodyshop, jobRO, insertAuditTrail, set
 
   const handleFinish = async ({ removefromproduction, ...values }) => {
     setLoading(true);
+    
+    // Validate that all joblines have valid IDs
+    const joblinesWithIds = values.joblines.filter(jl => jl && jl.id);
+    if (joblinesWithIds.length !== values.joblines.length) {
+      notification.error({
+        title: t("jobs.errors.invalidjoblines"),
+        message: t("jobs.errors.missingjoblineids")
+      });
+      setLoading(false);
+      return;
+    }
+    
     const result = await client.mutate({
       mutation: generateJobLinesUpdatesForInvoicing(values.joblines)
     });
     if (result.errors) {
+      setLoading(false);
       return; // Abandon the rest of the close.
     }
 
diff --git a/client/src/translations/en_us/common.json b/client/src/translations/en_us/common.json
index d1f215e60..c95876666 100644
--- a/client/src/translations/en_us/common.json
+++ b/client/src/translations/en_us/common.json
@@ -1676,7 +1676,9 @@
         "deleted": "Error deleting Job. {{error}}",
         "exporting": "Error exporting Job. {{error}}",
         "exporting-partner": "Unable to connect to partner application. Please ensure it is running and logged in.",
+        "invalidjoblines": "Job has invalid job lines.",
         "invoicing": "Error invoicing Job. {{error}}",
+        "missingjoblineids": "Missing job line IDs for job lines.",
         "noaccess": "This Job does not exist or you do not have access to it.",
         "nodamage": "No damage points on estimate.",
         "nodates": "No dates specified for this Job.",
diff --git a/client/src/translations/es/common.json b/client/src/translations/es/common.json
index 1b9c1f08d..70cd2b5da 100644
--- a/client/src/translations/es/common.json
+++ b/client/src/translations/es/common.json
@@ -1674,7 +1674,9 @@
         "deleted": "Error al eliminar el trabajo.",
         "exporting": "",
         "exporting-partner": "",
+        "invalidjoblines": "",
         "invoicing": "",
+        "missingjoblineids": "",
         "noaccess": "Este trabajo no existe o no tiene acceso a él.",
         "nodamage": "",
         "nodates": "No hay fechas especificadas para este trabajo.",
diff --git a/client/src/translations/fr/common.json b/client/src/translations/fr/common.json
index 490063ba1..e199a33b2 100644
--- a/client/src/translations/fr/common.json
+++ b/client/src/translations/fr/common.json
@@ -1674,7 +1674,9 @@
         "deleted": "Erreur lors de la suppression du travail.",
         "exporting": "",
         "exporting-partner": "",
+        "invalidjoblines": "",
         "invoicing": "",
+        "missingjoblineids": "",
         "noaccess": "Ce travail n'existe pas ou vous n'y avez pas accès.",
         "nodamage": "",
         "nodates": "Aucune date spécifiée pour ce travail.",