diff --git a/frontend/src/components/wallet/WalletMismatchBanner.test.tsx b/frontend/src/components/wallet/WalletMismatchBanner.test.tsx
new file mode 100644
index 00000000..f582f9c7
--- /dev/null
+++ b/frontend/src/components/wallet/WalletMismatchBanner.test.tsx
@@ -0,0 +1,219 @@
+import { describe, it, expect, vi, beforeEach } from "vitest";
+import { render, screen, fireEvent } from "@testing-library/react";
+import {
+  WalletMismatchBanner,
+  resolveSupportedNetworkId,
+} from "./WalletMismatchBanner";
+
+const mockUseWallet = vi.fn();
+const mockUseNetwork = vi.fn();
+
+vi.mock("@/context/wallet-context", () => ({
+  useWallet: () => mockUseWallet(),
+}));
+
+vi.mock("@/context/NetworkContext", () => ({
+  useNetwork: () => mockUseNetwork(),
+}));
+
+describe("resolveSupportedNetworkId", () => {
+  it("maps mainnet and public passphrases to mainnet", () => {
+    expect(resolveSupportedNetworkId("Mainnet")).toBe("mainnet");
+    expect(
+      resolveSupportedNetworkId("Public Global Stellar Network ; September 2015"),
+    ).toBe("mainnet");
+  });
+
+  it("maps testnet and SDF testnet passphrases to testnet", () => {
+    expect(resolveSupportedNetworkId("Testnet")).toBe("testnet");
+    expect(resolveSupportedNetworkId("Test SDF Network ; September 2015")).toBe(
+      "testnet",
+    );
+  });
+
+  it("maps futurenet and sandbox strings to their respective network IDs", () => {
+    expect(resolveSupportedNetworkId("Futurenet")).toBe("futurenet");
+    expect(
+      resolveSupportedNetworkId("Test SDF Future Network ; October 2022"),
+    ).toBe("futurenet");
+    expect(resolveSupportedNetworkId("Local Sandbox")).toBe("sandbox");
+    expect(resolveSupportedNetworkId("Standalone Network ; February 2017")).toBe(
+      "sandbox",
+    );
+  });
+
+  it("returns null for unknown custom networks or empty strings", () => {
+    expect(resolveSupportedNetworkId("")).toBeNull();
+    expect(resolveSupportedNetworkId("Custom Private Net")).toBeNull();
+  });
+});
+
+describe("WalletMismatchBanner", () => {
+  const connectMock = vi.fn();
+  const setNetworkIdMock = vi.fn();
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+  });
+
+  it("renders nothing when no wallet session is active", () => {
+    mockUseWallet.mockReturnValue({
+      session: null,
+      connect: connectMock,
+      selectedWalletId: null,
+    });
+    mockUseNetwork.mockReturnValue({
+      network: { id: "testnet", name: "Testnet" },
+      networkId: "testnet",
+      setNetworkId: setNetworkIdMock,
+      isHydrated: true,
+    });
+
+    const { container } = render(<WalletMismatchBanner />);
+    expect(container.firstChild).toBeNull();
+  });
+
+  it("renders nothing when wallet network matches app network", () => {
+    mockUseWallet.mockReturnValue({
+      session: {
+        walletId: "freighter",
+        publicKey: "GABC123",
+        network: "Test SDF Network ; September 2015",
+      },
+      connect: connectMock,
+      selectedWalletId: "freighter",
+    });
+    mockUseNetwork.mockReturnValue({
+      network: { id: "testnet", name: "Testnet" },
+      networkId: "testnet",
+      setNetworkId: setNetworkIdMock,
+      isHydrated: true,
+    });
+
+    const { container } = render(<WalletMismatchBanner />);
+    expect(container.firstChild).toBeNull();
+  });
+
+  it("renders role='alert' banner with bold badges for wallet and app networks when mismatched", () => {
+    mockUseWallet.mockReturnValue({
+      session: {
+        walletId: "freighter",
+        publicKey: "GABC123",
+        network: "Public Global Stellar Network ; September 2015",
+      },
+      connect: connectMock,
+      selectedWalletId: "freighter",
+    });
+    mockUseNetwork.mockReturnValue({
+      network: { id: "testnet", name: "Testnet" },
+      networkId: "testnet",
+      setNetworkId: setNetworkIdMock,
+      isHydrated: true,
+    });
+
+    render(<WalletMismatchBanner />);
+
+    const alert = screen.getByRole("alert");
+    expect(alert).toBeInTheDocument();
+
+    const walletBadge = screen.getByTestId("wallet-network-badge");
+    const appBadge = screen.getByTestId("app-network-badge");
+    expect(walletBadge.tagName).toBe("STRONG");
+    expect(walletBadge).toHaveTextContent("Mainnet");
+    expect(appBadge.tagName).toBe("STRONG");
+    expect(appBadge).toHaveTextContent("Testnet");
+  });
+
+  it("updates app network setting when 'Switch App to Wallet Network' is clicked", () => {
+    mockUseWallet.mockReturnValue({
+      session: {
+        walletId: "freighter",
+        publicKey: "GABC123",
+        network: "Mainnet",
+      },
+      connect: connectMock,
+      selectedWalletId: "freighter",
+    });
+    mockUseNetwork.mockReturnValue({
+      network: { id: "testnet", name: "Testnet" },
+      networkId: "testnet",
+      setNetworkId: setNetworkIdMock,
+      isHydrated: true,
+    });
+
+    render(<WalletMismatchBanner />);
+
+    const switchButton = screen.getByRole("button", {
+      name: /Switch App to Wallet Network/i,
+    });
+    expect(switchButton).not.toBeDisabled();
+    fireEvent.click(switchButton);
+
+    expect(setNetworkIdMock).toHaveBeenCalledTimes(1);
+    expect(setNetworkIdMock).toHaveBeenCalledWith("mainnet");
+  });
+
+  it("disables 'Switch App to Wallet Network' when wallet reports an unsupported custom network", () => {
+    mockUseWallet.mockReturnValue({
+      session: {
+        walletId: "freighter",
+        publicKey: "GABC123",
+        network: "Custom Private Chain",
+      },
+      connect: connectMock,
+      selectedWalletId: "freighter",
+    });
+    mockUseNetwork.mockReturnValue({
+      network: { id: "testnet", name: "Testnet" },
+      networkId: "testnet",
+      setNetworkId: setNetworkIdMock,
+      isHydrated: true,
+    });
+
+    render(<WalletMismatchBanner />);
+
+    const switchButton = screen.getByRole("button", {
+      name: /Switch App to Wallet Network/i,
+    });
+    expect(switchButton).toBeDisabled();
+  });
+
+  it("queries wallet connection on 'Re-check Connection' click and dismisses banner when resolved", () => {
+    let currentSession = {
+      walletId: "freighter" as const,
+      publicKey: "GABC123",
+      network: "Mainnet",
+    };
+
+    mockUseWallet.mockImplementation(() => ({
+      session: currentSession,
+      connect: connectMock,
+      selectedWalletId: "freighter",
+    }));
+    mockUseNetwork.mockReturnValue({
+      network: { id: "testnet", name: "Testnet" },
+      networkId: "testnet",
+      setNetworkId: setNetworkIdMock,
+      isHydrated: true,
+    });
+
+    const { rerender } = render(<WalletMismatchBanner />);
+    expect(screen.getByRole("alert")).toBeInTheDocument();
+
+    const recheckButton = screen.getByRole("button", {
+      name: /Re-check Connection/i,
+    });
+    fireEvent.click(recheckButton);
+    expect(connectMock).toHaveBeenCalledTimes(1);
+    expect(connectMock).toHaveBeenCalledWith("freighter");
+
+    // Simulate wallet session updating to match app network after re-check
+    currentSession = {
+      walletId: "freighter",
+      publicKey: "GABC123",
+      network: "Testnet",
+    };
+    rerender(<WalletMismatchBanner />);
+    expect(screen.queryByRole("alert")).not.toBeInTheDocument();
+  });
+});
diff --git a/frontend/src/components/wallet/WalletMismatchBanner.tsx b/frontend/src/components/wallet/WalletMismatchBanner.tsx
index 005a2573..cfb55972 100644
--- a/frontend/src/components/wallet/WalletMismatchBanner.tsx
+++ b/frontend/src/components/wallet/WalletMismatchBanner.tsx
@@ -1,12 +1,112 @@
 "use client";
 
-import { AlertTriangle, RefreshCw } from "lucide-react";
+import { AlertTriangle, ArrowLeftRight, RefreshCw } from "lucide-react";
 import { useWallet } from "@/context/wallet-context";
 import { useNetwork } from "@/context/NetworkContext";
 import { formatNetwork } from "@/lib/wallet";
+import type { NetworkId } from "@/lib/stellar-config";
+
+/**
+ * Resolves a wallet-reported network string or passphrase to a supported app NetworkId.
+ */
+export function resolveSupportedNetworkId(walletNetwork: string): NetworkId | null {
+  const raw = walletNetwork.trim().toLowerCase();
+  if (!raw) return null;
+
+  if (raw.includes("future")) {
+    return "futurenet";
+  }
+
+  if (raw.includes("sandbox") || raw.includes("standalone") || raw.includes("local")) {
+    return "sandbox";
+  }
+
+  const formatted = formatNetwork(walletNetwork).trim().toLowerCase();
+  if (formatted === "mainnet") {
+    return "mainnet";
+  }
+
+  if (formatted === "testnet") {
+    return "testnet";
+  }
+
+  return null;
+}
 
 export function WalletMismatchBanner() {
-  const { session, connect, selectedWalletId } = useWallet(); const { network } = useNetwork();
-  if (!session || formatNetwork(session.network).toLowerCase() === network.name.toLowerCase()) return null;
-  return <div role="alert" className="flex items-center justify-between gap-4 border-b border-orange-400/30 bg-orange-400/10 px-6 py-2 text-sm text-orange-100"><span className="flex items-center gap-2"><AlertTriangle size={16} />Wallet is on {formatNetwork(session.network)}; app is using {network.name}. Transactions may fail.</span><button onClick={() => { if (selectedWalletId) void connect(selectedWalletId); }} className="flex shrink-0 items-center gap-2 rounded border border-orange-300/40 px-3 py-1 text-xs font-semibold"><RefreshCw size={13} />Reconnect wallet</button></div>;
+  const { session, connect, selectedWalletId } = useWallet();
+  const { network, setNetworkId } = useNetwork();
+
+  if (!session) return null;
+
+  const walletNetworkLabel = formatNetwork(session.network);
+  const targetNetworkId = resolveSupportedNetworkId(session.network);
+
+  if (
+    walletNetworkLabel.toLowerCase() === network.name.toLowerCase() ||
+    (targetNetworkId !== null && targetNetworkId === network.id)
+  ) {
+    return null;
+  }
+
+  const handleSwitchAppNetwork = () => {
+    if (targetNetworkId) {
+      setNetworkId(targetNetworkId);
+    }
+  };
+
+  const handleRecheckConnection = () => {
+    const walletIdToCheck = selectedWalletId ?? session.walletId;
+    if (walletIdToCheck) {
+      void connect(walletIdToCheck);
+    }
+  };
+
+  return (
+    <div
+      role="alert"
+      className="flex flex-wrap items-center justify-between gap-4 border-b border-orange-400/30 bg-orange-400/10 px-6 py-2 text-sm text-orange-100"
+    >
+      <span className="flex flex-wrap items-center gap-2">
+        <AlertTriangle size={16} className="shrink-0" aria-hidden="true" />
+        <span>
+          Wallet is on{" "}
+          <strong
+            data-testid="wallet-network-badge"
+            className="inline-flex items-center rounded bg-orange-400/20 px-2 py-0.5 font-bold text-orange-50"
+          >
+            {walletNetworkLabel}
+          </strong>
+          ; app is using{" "}
+          <strong
+            data-testid="app-network-badge"
+            className="inline-flex items-center rounded bg-orange-400/20 px-2 py-0.5 font-bold text-orange-50"
+          >
+            {network.name}
+          </strong>
+          . Transactions may fail.
+        </span>
+      </span>
+
+      <div className="flex shrink-0 items-center gap-2">
+        <button
+          type="button"
+          onClick={handleSwitchAppNetwork}
+          disabled={!targetNetworkId}
+          className="flex items-center gap-1.5 rounded border border-orange-300/40 bg-orange-400/15 px-3 py-1 text-xs font-semibold transition-colors hover:bg-orange-400/25 disabled:cursor-not-allowed disabled:opacity-50"
+        >
+          <ArrowLeftRight size={13} aria-hidden="true" />
+          Switch App to Wallet Network
+        </button>
+        <button
+          type="button"
+          onClick={handleRecheckConnection}
+          className="flex items-center gap-1.5 rounded border border-orange-300/40 px-3 py-1 text-xs font-semibold transition-colors hover:bg-orange-400/20"
+        >
+          <RefreshCw size={13} aria-hidden="true" />
+          Re-check Connection
+        </button>
+      </div>
+    </div>
+  );
 }
\ No newline at end of file