diff --git a/.changeset/quiet-feedback-errors.md b/.changeset/quiet-feedback-errors.md
new file mode 100644
index 000000000..6ce274a1d
--- /dev/null
+++ b/.changeset/quiet-feedback-errors.md
@@ -0,0 +1,5 @@
+---
+"@reflag/browser-sdk": patch
+---
+
+Treat unsuccessful feedback form submissions as errors instead of showing success and invoking `onAfterSubmit` with unsaved feedback. Applies to manual and automated forms, and allows retrying Send.
diff --git a/packages/browser-sdk/src/client.ts b/packages/browser-sdk/src/client.ts
index 4f63bbbef..17fad6e52 100644
--- a/packages/browser-sdk/src/client.ts
+++ b/packages/browser-sdk/src/client.ts
@@ -1199,11 +1199,13 @@ export class ReflagClient {
           return { feedbackId: undefined };
         },
         onSubmit: async (data) => {
-          // Default onSubmit handler
-          await this.feedback({
+          const res = await this.feedback({
             ...feedbackData,
             ...data,
           });
+          if (!res?.ok) {
+            throw new Error("Couldn't submit feedback. Please try again.");
+          }
 
           options.onAfterSubmit?.(data);
         },
diff --git a/packages/browser-sdk/src/feedback/feedback.ts b/packages/browser-sdk/src/feedback/feedback.ts
index 1a68eeed8..dd7146bc3 100644
--- a/packages/browser-sdk/src/feedback/feedback.ts
+++ b/packages/browser-sdk/src/feedback/feedback.ts
@@ -435,7 +435,10 @@ export class AutoFeedback {
             return { feedbackId: res.feedbackId };
           },
           onSubmit: async (data) => {
-            await replyCallback(data);
+            const res = await replyCallback(data);
+            if (!res?.feedbackId) {
+              throw new Error("Couldn't submit feedback. Please try again.");
+            }
             options.onAfterSubmit?.(data);
           },
           onDismiss: () => replyCallback(null),
diff --git a/packages/browser-sdk/test/feedbackSubmitErrors.test.ts b/packages/browser-sdk/test/feedbackSubmitErrors.test.ts
new file mode 100644
index 000000000..aecd4a847
--- /dev/null
+++ b/packages/browser-sdk/test/feedbackSubmitErrors.test.ts
@@ -0,0 +1,65 @@
+import { afterEach, expect, test, vi } from "vitest";
+
+import { ReflagClient } from "../src/client";
+import { AutoFeedback } from "../src/feedback/feedback";
+import * as feedbackUi from "../src/feedback/ui";
+import { HttpClient } from "../src/httpClient";
+import { testLogger } from "./testLogger";
+
+const data = { question: "How was it?", score: 4, comment: "Useful!" };
+
+afterEach(() => vi.restoreAllMocks());
+
+test.each(["manual", "automated"] as const)(
+  "%s feedback rejects a failed Send without notifying, then allows retry",
+  async (source) => {
+    const open = vi
+      .spyOn(feedbackUi, "openFeedbackForm")
+      .mockImplementation(() => undefined);
+    const onAfterSubmit = vi.fn();
+    let status = 200;
+    vi.spyOn(HttpClient.prototype, "post").mockImplementation(async () =>
+      Response.json(
+        status === 200 ? { feedbackId: "123" } : { message: "Unavailable" },
+        { status },
+      ),
+    );
+
+    if (source === "manual") {
+      const client = new ReflagClient({
+        publishableKey: "test-key",
+        user: { id: "user" },
+        logger: testLogger,
+      });
+      client.requestFeedback({ flagKey: "flag", onAfterSubmit });
+      await vi.waitFor(() => expect(open).toHaveBeenCalledOnce());
+    } else {
+      const auto = new AutoFeedback(
+        "https://front.reflag.com",
+        testLogger,
+        new HttpClient("test-key"),
+        (_prompt, handlers) => handlers.openFeedbackForm({ onAfterSubmit }),
+        "user",
+      );
+      await auto.triggerFeedbackPrompt(
+        "user",
+        {
+          question: data.question,
+          promptId: "prompt",
+          featureId: "feature",
+          showAfter: new Date(),
+          showBefore: new Date(Date.now() + 60000),
+        },
+        vi.fn(),
+      );
+    }
+
+    const { onSubmit } = open.mock.calls[0]![0];
+    status = 500;
+    await expect(onSubmit(data)).rejects.toThrow("Couldn't submit feedback");
+    expect(onAfterSubmit).not.toHaveBeenCalled();
+
+    status = 200;
+    await expect(onSubmit(data)).resolves.toBeUndefined();
+  },
+);