diff --git a/frontend/src/features/web/PairingScreen.test.tsx b/frontend/src/features/web/PairingScreen.test.tsx
new file mode 100644
index 0000000..4aab76a
--- /dev/null
+++ b/frontend/src/features/web/PairingScreen.test.tsx
@@ -0,0 +1,77 @@
+/**
+ * #75 — the pairing code is uppercase hex (`3F7A9C21`), not digits:
+ *  - the field must summon the text keyboard, not the numeric keypad;
+ *  - a lowercase entry must reach `session.pair()` uppercased and space-free,
+ *    because the server compares the code strictly.
+ */
+import { describe, it, expect, vi } from "vitest";
+import { fireEvent, render, screen } from "@testing-library/react";
+
+import { WebSession } from "@/adapters/http";
+import type { FetchLike } from "@/adapters/http/httpInvoker";
+import type { FlagStore } from "@/adapters/http/webSession";
+import { PairingScreen } from "./PairingScreen";
+
+function memStore(): FlagStore {
+  const map = new Map<string, string>();
+  return {
+    getItem: (k) => map.get(k) ?? null,
+    setItem: (k, v) => void map.set(k, v),
+    removeItem: (k) => void map.delete(k),
+  };
+}
+
+const okFetch: FetchLike = async () => ({
+  ok: true,
+  status: 200,
+  json: async () => ({ ok: true }),
+  text: async () => "{}",
+});
+
+function setup() {
+  const session = new WebSession({ baseUrl: "https://h", fetchImpl: okFetch, store: memStore() });
+  const pair = vi.spyOn(session, "pair");
+  const onPaired = vi.fn();
+  render(<PairingScreen session={session} onPaired={onPaired} />);
+  return { pair, onPaired };
+}
+
+describe("PairingScreen code field", () => {
+  it("asks for the text keyboard, not the numeric keypad", () => {
+    setup();
+    const field = screen.getByLabelText("Code d'appairage");
+
+    expect(field.getAttribute("inputmode")).toBe("text");
+    expect(field.getAttribute("autocapitalize")).toBe("characters");
+    expect(field.getAttribute("autocomplete")).toBe("one-time-code");
+  });
+
+  it("describes the code without lying about its shape", () => {
+    setup();
+    const field = screen.getByLabelText("Code d'appairage");
+
+    expect(field.getAttribute("placeholder")).toBe("p. ex. AB12CD34");
+    expect(screen.getByText("8 caractères : chiffres et lettres A-F")).toBeTruthy();
+  });
+
+  it("uppercases and strips spaces before pairing", async () => {
+    const { pair, onPaired } = setup();
+
+    fireEvent.change(screen.getByLabelText("Code d'appairage"), {
+      target: { value: " ab12cd34 " },
+    });
+    fireEvent.click(screen.getByRole("button", { name: "Appairer" }));
+
+    await vi.waitFor(() => expect(onPaired).toHaveBeenCalled());
+    expect(pair).toHaveBeenCalledWith("AB12CD34");
+  });
+
+  it("keeps submit disabled for a blank code", () => {
+    setup();
+    const submit = screen.getByRole("button", { name: "Appairer" });
+    expect((submit as HTMLButtonElement).disabled).toBe(true);
+
+    fireEvent.change(screen.getByLabelText("Code d'appairage"), { target: { value: "   " } });
+    expect((submit as HTMLButtonElement).disabled).toBe(true);
+  });
+});
diff --git a/frontend/src/features/web/PairingScreen.tsx b/frontend/src/features/web/PairingScreen.tsx
index 32bb704..89edf46 100644
--- a/frontend/src/features/web/PairingScreen.tsx
+++ b/frontend/src/features/web/PairingScreen.tsx
@@ -31,6 +31,14 @@ function describe(e: unknown): string {
   return String(e);
 }
 
+/**
+ * The server compares the code strictly against the uppercase hex it generated,
+ * so the UI uppercases (and drops stray spaces) before sending.
+ */
+function normalize(raw: string): string {
+  return raw.replace(/\s+/g, "").toUpperCase();
+}
+
 export function PairingScreen({ session, onPaired }: PairingScreenProps) {
   const [code, setCode] = useState("");
   const [error, setError] = useState<string | null>(null);
@@ -38,12 +46,12 @@ export function PairingScreen({ session, onPaired }: PairingScreenProps) {
 
   async function submit(e: FormEvent): Promise<void> {
     e.preventDefault();
-    const trimmed = code.trim();
-    if (!trimmed || busy) return;
+    const normalized = normalize(code);
+    if (!normalized || busy) return;
     setBusy(true);
     setError(null);
     try {
-      await session.pair(trimmed);
+      await session.pair(normalized);
       onPaired();
     } catch (err) {
       setError(describe(err));
@@ -64,20 +72,20 @@ export function PairingScreen({ session, onPaired }: PairingScreenProps) {
             </p>
           </div>
 
-          <Field label="Code d'appairage">
+          <Field label="Code d'appairage" hint="8 caractères : chiffres et lettres A-F">
             {({ id, describedBy }) => (
               <Input
                 id={id}
                 aria-describedby={describedBy}
                 value={code}
                 onChange={(e) => setCode(e.target.value)}
-                placeholder="p. ex. 4821-93"
+                placeholder="p. ex. AB12CD34"
                 autoFocus
                 autoComplete="one-time-code"
-                // #69 — phones: summon the numeric-ish keypad for a pairing code
-                // and keep the OS from "helpfully" capitalising/correcting it.
-                inputMode="numeric"
-                autoCapitalize="off"
+                // #75 — the code mixes digits and letters, so phones need the
+                // text keyboard; uppercase it on the way in, never autocorrect.
+                inputMode="text"
+                autoCapitalize="characters"
                 autoCorrect="off"
                 spellCheck={false}
                 disabled={busy}
@@ -92,7 +100,7 @@ export function PairingScreen({ session, onPaired }: PairingScreenProps) {
             </p>
           )}
 
-          <Button type="submit" disabled={busy || code.trim().length === 0}>
+          <Button type="submit" disabled={busy || normalize(code).length === 0}>
             {busy ? "Appairage…" : "Appairer"}
           </Button>
         </form>