diff --git a/apps/coordinator/e2e/pages/SendTab.ts b/apps/coordinator/e2e/pages/SendTab.ts
index 5cb37c9c3..93197524e 100644
--- a/apps/coordinator/e2e/pages/SendTab.ts
+++ b/apps/coordinator/e2e/pages/SendTab.ts
@@ -92,6 +92,23 @@ export class SendTab {
     await btn.click();
   }
 
+  async importPsbtFile(psbtPath: string) {
+    await this.page.getByText("Import PSBT").scrollIntoViewIfNeeded();
+    await this.page.getByRole("combobox", { name: /import method/i }).click();
+    await this.page.getByRole("option", { name: /file upload/i }).click();
+    await this.page.locator('input[type="file"]').setInputFiles(psbtPath);
+    await this.page.getByRole("button", { name: /import psbt file/i }).click();
+  }
+
+  async expectImportErrorBlocksSigning() {
+    await expect(this.page.getByRole("alert")).toBeVisible({
+      timeout: 10000,
+    });
+    await expect(
+      this.page.getByRole("button", { name: /sign transaction/i }),
+    ).not.toBeVisible();
+  }
+
   async downloadUnsignedPsbt(savePath: string): Promise<string> {
     const btn = this.page.locator(
       'button[type=button]:has-text("Download Unsigned PSBT")',
diff --git a/apps/coordinator/e2e/tests/mutate/transaction-flow.spec.ts b/apps/coordinator/e2e/tests/mutate/transaction-flow.spec.ts
index c9b56dfd5..1e74fe3f2 100644
--- a/apps/coordinator/e2e/tests/mutate/transaction-flow.spec.ts
+++ b/apps/coordinator/e2e/tests/mutate/transaction-flow.spec.ts
@@ -44,6 +44,16 @@ test.describe.serial("Transaction Creation and Signing", () => {
     await walletNav.switchToTab("Send");
   });
 
+  test("invalid PSBT upload: shows error and blocks signing", async ({
+    sendTab,
+  }) => {
+    const invalidPsbtPath = path.join(uploadDir, "invalid.psbt");
+    fs.writeFileSync(invalidPsbtPath, "this-is-not-a-valid-psbt");
+
+    await sendTab.importPsbtFile(invalidPsbtPath);
+    await sendTab.expectImportErrorBlocksSigning();
+  });
+
   test("auto coin selection: create, sign, broadcast", async ({
     sendTab,
     signTab,