diff --git a/src/app/(customer)/settings/page.tsx b/src/app/(customer)/settings/page.tsx
index 4582f71..4eafa9f 100644
--- a/src/app/(customer)/settings/page.tsx
+++ b/src/app/(customer)/settings/page.tsx
@@ -1,5 +1,5 @@
 import type { Metadata } from "next";
-import { Bell, Gift, LogIn } from "lucide-react";
+import { Bell, ChevronRight, Gift, LogIn, User } from "lucide-react";
 import Link from "next/link";
 import { auth } from "@/auth";
 import { Button } from "@/components/ui/button";
@@ -13,6 +13,12 @@ import { InstallAppButton } from "@/features/pwa/components/install-app-button";
 export const metadata: Metadata = { title: "Settings" };
 export const dynamic = "force-dynamic";
 
+const SETTINGS_LINKS = [
+  { href: "/settings/preferred-barber", label: "Preferred Barber", icon: User },
+  { href: "/loyalty", label: "Loyalty Card", icon: Gift },
+  { href: "/settings/notifications", label: "Notifications", icon: Bell },
+] as const;
+
 export default async function CustomerSettingsPage() {
   const session = await auth();
 
@@ -34,8 +40,9 @@ export default async function CustomerSettingsPage() {
     );
   }
 
-  const [customerProfile, branding] = await Promise.all([
+  const [customerProfile, user, branding] = await Promise.all([
     prisma.customerProfile.findUnique({ where: { userId: session.user.id } }),
+    prisma.user.findUnique({ where: { id: session.user.id }, select: { image: true } }),
     getBranding(),
   ]);
 
@@ -49,22 +56,20 @@ export default async function CustomerSettingsPage() {
             : (session.user.name ?? "Signed-in customer")
         }
         meta={customerProfile?.email ?? session.user.email}
-        avatarUrl={session.user.image ?? undefined}
+        avatarUrl={user?.image ?? undefined}
+        editHref="/settings/profile"
       />
-      <div className="space-y-2">
-        <Link
-          href="/loyalty"
-          className="border-line flex items-center gap-3 rounded-xl border bg-white px-4 py-3 text-sm font-bold"
-        >
-          <Gift className="h-4 w-4" aria-hidden="true" /> Loyalty card
-        </Link>
-        <Link
-          href="/settings/notifications"
-          className="border-line flex items-center gap-3 rounded-xl border bg-white px-4 py-3 text-sm font-bold"
-        >
-          <Bell className="h-4 w-4" aria-hidden="true" /> Notifications
-        </Link>
-      </div>
+      <ul className="divide-line divide-y rounded-md border border-line bg-white">
+        {SETTINGS_LINKS.map(({ href, label, icon: Icon }) => (
+          <li key={href}>
+            <Link href={href} className="hover:bg-stone flex items-center gap-3 px-5 py-4 text-sm font-bold">
+              <Icon className="text-muted h-5 w-5" aria-hidden="true" />
+              <span className="flex-1">{label}</span>
+              <ChevronRight className="text-muted h-4 w-4" aria-hidden="true" />
+            </Link>
+          </li>
+        ))}
+      </ul>
       <div className="border-line rounded-md border bg-white p-5">
         <p className="mb-3 text-sm font-bold">Get the app</p>
         <InstallAppButton businessName={branding.name} />
diff --git a/src/app/(customer)/settings/preferred-barber/page.tsx b/src/app/(customer)/settings/preferred-barber/page.tsx
new file mode 100644
index 0000000..9ac51e3
--- /dev/null
+++ b/src/app/(customer)/settings/preferred-barber/page.tsx
@@ -0,0 +1,38 @@
+import type { Metadata } from "next";
+import { redirect } from "next/navigation";
+import { auth } from "@/auth";
+import { TopNav } from "@/components/navigation/top-nav";
+import { getPrimaryBusiness } from "@/lib/business/get-primary-business";
+import { prisma } from "@/lib/db/prisma";
+import { PreferredBarberPicker } from "@/features/customer/components/preferred-barber-picker";
+
+export const metadata: Metadata = { title: "Preferred Barber" };
+export const dynamic = "force-dynamic";
+
+export default async function PreferredBarberPage() {
+  const session = await auth();
+  if (!session?.user) redirect("/sign-in?callbackUrl=/settings/preferred-barber");
+
+  const [business, customerProfile] = await Promise.all([
+    getPrimaryBusiness(),
+    prisma.customerProfile.findUnique({ where: { userId: session.user.id } }),
+  ]);
+
+  const staff = await prisma.staffProfile.findMany({
+    where: { businessId: business.id, status: "ACTIVE", isBookableOnline: true },
+    include: { user: { select: { name: true, image: true } } },
+  });
+
+  return (
+    <div className="pb-12">
+      <TopNav title="Preferred Barber" onBack sticky className="bg-stone" />
+      <main className="mx-auto max-w-2xl space-y-4 px-6 py-6">
+        <p className="text-muted text-sm">Chosen for you by default when booking — you can still pick anyone else.</p>
+        <PreferredBarberPicker
+          staff={staff.map((s) => ({ id: s.id, name: s.user.name ?? "Barber", avatarUrl: s.user.image ?? undefined }))}
+          initialPreferredId={customerProfile?.preferredBarberId ?? null}
+        />
+      </main>
+    </div>
+  );
+}
diff --git a/src/app/(customer)/settings/profile/page.tsx b/src/app/(customer)/settings/profile/page.tsx
new file mode 100644
index 0000000..4a08312
--- /dev/null
+++ b/src/app/(customer)/settings/profile/page.tsx
@@ -0,0 +1,38 @@
+import type { Metadata } from "next";
+import { redirect } from "next/navigation";
+import { auth } from "@/auth";
+import { TopNav } from "@/components/navigation/top-nav";
+import { prisma } from "@/lib/db/prisma";
+import { CustomerProfileForm } from "@/features/customer/components/customer-profile-form";
+
+export const metadata: Metadata = { title: "Edit Profile" };
+export const dynamic = "force-dynamic";
+
+export default async function CustomerEditProfilePage() {
+  const session = await auth();
+  if (!session?.user) redirect("/sign-in?callbackUrl=/settings/profile");
+
+  const [customerProfile, user] = await Promise.all([
+    prisma.customerProfile.findUnique({ where: { userId: session.user.id } }),
+    prisma.user.findUnique({ where: { id: session.user.id }, select: { image: true } }),
+  ]);
+
+  const [sessionFirstName, ...sessionLastNameParts] = (session.user.name ?? "").trim().split(" ");
+
+  return (
+    <div className="pb-12">
+      <TopNav title="Edit Profile" onBack sticky className="bg-stone" />
+      <main className="mx-auto max-w-2xl space-y-6 px-6 py-6">
+        <CustomerProfileForm
+          initial={{
+            firstName: customerProfile?.firstName ?? sessionFirstName ?? "",
+            lastName: customerProfile?.lastName ?? sessionLastNameParts.join(" "),
+            email: customerProfile?.email ?? session.user.email ?? "",
+            phone: customerProfile?.phone ?? "",
+            image: user?.image ?? "",
+          }}
+        />
+      </main>
+    </div>
+  );
+}
diff --git a/src/components/ui/profile-card.tsx b/src/components/ui/profile-card.tsx
index dbbf7b2..984ba73 100644
--- a/src/components/ui/profile-card.tsx
+++ b/src/components/ui/profile-card.tsx
@@ -1,4 +1,5 @@
 import Image from "next/image";
+import Link from "next/link";
 import { Pencil } from "lucide-react";
 import type { ReactNode } from "react";
 import { Card } from "@/components/ui/card";
@@ -8,10 +9,14 @@ export interface ProfileCardProps {
   meta?: ReactNode;
   avatarUrl?: string;
   onEdit?: () => void;
+  /** Renders the edit-pencil as a `<Link>` instead of a button — lets a Server Component page use the edit affordance without becoming a Client Component. Ignored if `onEdit` is also passed. */
+  editHref?: string;
 }
 
 /** Avatar + name + meta + edit-pencil pattern reused across nearly every settings/profile screen. */
-export function ProfileCard({ name, meta, avatarUrl, onEdit }: ProfileCardProps) {
+export function ProfileCard({ name, meta, avatarUrl, onEdit, editHref }: ProfileCardProps) {
+  const editButtonClassName = "flex h-10 w-10 items-center justify-center rounded-full bg-stone text-ink";
+
   return (
     <Card className="flex items-center gap-4 p-5">
       {avatarUrl ? (
@@ -31,15 +36,16 @@ export function ProfileCard({ name, meta, avatarUrl, onEdit }: ProfileCardProps)
         <h2 className="text-lg font-bold">{name}</h2>
         {meta && <div className="mt-0.5 text-xs text-muted">{meta}</div>}
       </div>
-      {onEdit && (
-        <button
-          type="button"
-          onClick={onEdit}
-          aria-label={`Edit ${name}`}
-          className="flex h-10 w-10 items-center justify-center rounded-full bg-stone text-ink"
-        >
+      {onEdit ? (
+        <button type="button" onClick={onEdit} aria-label={`Edit ${name}`} className={editButtonClassName}>
           <Pencil className="h-3.5 w-3.5" aria-hidden="true" />
         </button>
+      ) : (
+        editHref && (
+          <Link href={editHref} aria-label={`Edit ${name}`} className={editButtonClassName}>
+            <Pencil className="h-3.5 w-3.5" aria-hidden="true" />
+          </Link>
+        )
       )}
     </Card>
   );
diff --git a/src/features/customer/actions/profile.ts b/src/features/customer/actions/profile.ts
new file mode 100644
index 0000000..6300e8f
--- /dev/null
+++ b/src/features/customer/actions/profile.ts
@@ -0,0 +1,104 @@
+"use server";
+
+import { auth } from "@/auth";
+import { prisma } from "@/lib/db/prisma";
+import { customerProfileSchema } from "@/features/customer/schemas";
+import {
+  CUSTOMER_AVATAR_CATEGORY,
+  setCustomerAvatar,
+  updateCustomerProfile,
+  updatePreferredBarber,
+} from "@/services/customer/customer.service";
+import { deleteMediaFile, isAllowedMediaMimeType, MEDIA_MAX_UPLOAD_BYTES, storeMediaFile } from "@/lib/media/media-storage";
+
+export interface CustomerProfileActionResult {
+  success: boolean;
+  error?: string;
+  /** Per-field errors, keyed by field name, for the form to surface inline. */
+  fieldErrors?: Record<string, string[] | undefined>;
+}
+
+export async function updateCustomerProfileAction(input: {
+  firstName: string;
+  lastName: string;
+  email: string;
+  phone: string;
+}): Promise<CustomerProfileActionResult> {
+  const session = await auth();
+  if (!session?.user?.id) return { success: false, error: "You must be signed in." };
+
+  const parsed = customerProfileSchema.safeParse(input);
+  if (!parsed.success) {
+    return { success: false, error: "Please fix the highlighted fields.", fieldErrors: parsed.error.flatten().fieldErrors };
+  }
+
+  const result = await updateCustomerProfile(prisma, { userId: session.user.id, ...parsed.data, phone: parsed.data.phone ?? "" });
+  if (!result.success) {
+    return {
+      success: false,
+      error: result.error,
+      fieldErrors: result.field ? { [result.field]: [result.error ?? ""] } : undefined,
+    };
+  }
+  return { success: true };
+}
+
+export async function updatePreferredBarberAction(staffId: string | null): Promise<CustomerProfileActionResult> {
+  const session = await auth();
+  if (!session?.user?.id) return { success: false, error: "You must be signed in." };
+
+  return updatePreferredBarber(prisma, { userId: session.user.id, staffId });
+}
+
+export interface CustomerAvatarActionResult {
+  success: boolean;
+  url?: string | null;
+  error?: string;
+}
+
+/**
+ * Uploads a customer's own profile photo straight from the device file
+ * picker — no Media Manager/library involved, unlike staff/service/branding
+ * images (see MediaPicker). Stored under its own category so it's never
+ * inserted as a MediaAsset row and therefore never browsable in that
+ * library. Takes effect immediately (writes User.image right away) rather
+ * than waiting for the rest of the profile form's Save, and deletes the
+ * previous photo file once the new one is safely persisted — but only if
+ * that previous file was one we stored (an OAuth-provided avatar URL is
+ * left alone).
+ */
+export async function uploadCustomerAvatarAction(formData: FormData): Promise<CustomerAvatarActionResult> {
+  const session = await auth();
+  if (!session?.user?.id) return { success: false, error: "You must be signed in." };
+
+  const file = formData.get("file");
+  if (!(file instanceof File)) return { success: false, error: "No file provided." };
+  if (!isAllowedMediaMimeType(file.type)) {
+    return { success: false, error: "Unsupported image type — use PNG, JPEG, WEBP, or GIF." };
+  }
+  if (file.size > MEDIA_MAX_UPLOAD_BYTES) {
+    return { success: false, error: `File is too large — max ${Math.floor(MEDIA_MAX_UPLOAD_BYTES / 1_000_000)}MB.` };
+  }
+
+  const buffer = Buffer.from(await file.arrayBuffer());
+  const stored = await storeMediaFile({ buffer, mimeType: file.type, category: CUSTOMER_AVATAR_CATEGORY });
+
+  const { previousUrl } = await setCustomerAvatar(prisma, { userId: session.user.id, url: stored.url });
+  if (previousUrl?.includes(`/${CUSTOMER_AVATAR_CATEGORY}/`)) {
+    await deleteMediaFile(previousUrl);
+  }
+
+  return { success: true, url: stored.url };
+}
+
+export async function removeCustomerAvatarAction(): Promise<CustomerAvatarActionResult> {
+  const session = await auth();
+  if (!session?.user?.id) return { success: false, error: "You must be signed in." };
+
+  const { previousUrl } = await setCustomerAvatar(prisma, { userId: session.user.id, url: null });
+  if (previousUrl?.includes(`/${CUSTOMER_AVATAR_CATEGORY}/`)) {
+    await deleteMediaFile(previousUrl);
+  }
+
+  return { success: true, url: null };
+}
diff --git a/src/features/customer/components/customer-avatar-picker.tsx b/src/features/customer/components/customer-avatar-picker.tsx
new file mode 100644
index 0000000..cc05387
--- /dev/null
+++ b/src/features/customer/components/customer-avatar-picker.tsx
@@ -0,0 +1,92 @@
+"use client";
+
+import { useRef, useState, useTransition } from "react";
+import { ImageOff, X } from "lucide-react";
+import { Button } from "@/components/ui/button";
+import { removeCustomerAvatarAction, uploadCustomerAvatarAction } from "@/features/customer/actions/profile";
+
+export interface CustomerAvatarPickerProps {
+  value: string | null;
+  onChange: (url: string | null) => void;
+}
+
+/**
+ * The customer's own profile photo — opens the device's native file picker
+ * directly and uploads immediately, unlike MediaPicker (staff/service/
+ * branding images), which opens the shared Media Manager library. Kept
+ * deliberately separate: a customer's photo is personal, not something an
+ * owner should be able to browse/reuse/reassign to something else.
+ */
+export function CustomerAvatarPicker({ value, onChange }: CustomerAvatarPickerProps) {
+  const inputRef = useRef<HTMLInputElement>(null);
+  const [error, setError] = useState<string | null>(null);
+  const [isPending, startTransition] = useTransition();
+
+  function handleFileChange(e: React.ChangeEvent<HTMLInputElement>) {
+    const file = e.target.files?.[0];
+    e.target.value = "";
+    if (!file) return;
+
+    setError(null);
+    const formData = new FormData();
+    formData.set("file", file);
+    startTransition(async () => {
+      const result = await uploadCustomerAvatarAction(formData);
+      if (!result.success) {
+        setError(result.error ?? "Couldn't upload your photo.");
+        return;
+      }
+      onChange(result.url ?? null);
+    });
+  }
+
+  function handleRemove() {
+    setError(null);
+    startTransition(async () => {
+      const result = await removeCustomerAvatarAction();
+      if (!result.success) {
+        setError(result.error ?? "Couldn't remove your photo.");
+        return;
+      }
+      onChange(null);
+    });
+  }
+
+  return (
+    <div className="w-full">
+      <p className="text-muted mb-2 ml-1 text-[10px] font-bold tracking-widest uppercase">Photo</p>
+      <div className="border-line flex items-center gap-4 rounded-xl border bg-white p-4">
+        <div className="bg-stone flex h-16 w-16 shrink-0 items-center justify-center overflow-hidden rounded-lg">
+          {value ? (
+            // eslint-disable-next-line @next/next/no-img-element -- local/user-supplied URLs, same pattern used app-wide
+            <img src={value} alt="" className="h-full w-full object-cover" />
+          ) : (
+            <ImageOff className="text-muted h-5 w-5" aria-hidden="true" />
+          )}
+        </div>
+        <div className="flex flex-1 flex-wrap gap-2">
+          <Button type="button" size="sm" variant="secondary" isLoading={isPending} onClick={() => inputRef.current?.click()}>
+            {value ? "Change" : "Choose image"}
+          </Button>
+          {value && (
+            <Button type="button" size="sm" variant="ghost" disabled={isPending} onClick={handleRemove}>
+              <X className="h-3.5 w-3.5" aria-hidden="true" /> Remove
+            </Button>
+          )}
+        </div>
+        <input
+          ref={inputRef}
+          type="file"
+          accept="image/png,image/jpeg,image/webp,image/gif"
+          className="sr-only"
+          onChange={handleFileChange}
+        />
+      </div>
+      {error && (
+        <p role="alert" className="text-danger mt-1.5 ml-1 text-xs font-medium">
+          {error}
+        </p>
+      )}
+    </div>
+  );
+}
diff --git a/src/features/customer/components/customer-profile-form.tsx b/src/features/customer/components/customer-profile-form.tsx
new file mode 100644
index 0000000..603fea7
--- /dev/null
+++ b/src/features/customer/components/customer-profile-form.tsx
@@ -0,0 +1,90 @@
+"use client";
+
+import { useRouter } from "next/navigation";
+import { useState, useTransition } from "react";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { CustomerAvatarPicker } from "@/features/customer/components/customer-avatar-picker";
+import { updateCustomerProfileAction } from "@/features/customer/actions/profile";
+
+export interface CustomerProfileFormInitial {
+  firstName: string;
+  lastName: string;
+  email: string;
+  phone: string;
+  image: string;
+}
+
+export function CustomerProfileForm({ initial }: { initial: CustomerProfileFormInitial }) {
+  const router = useRouter();
+  const [firstName, setFirstName] = useState(initial.firstName);
+  const [lastName, setLastName] = useState(initial.lastName);
+  const [email, setEmail] = useState(initial.email);
+  const [phone, setPhone] = useState(initial.phone);
+  const [image, setImage] = useState(initial.image);
+  const [error, setError] = useState<string | null>(null);
+  const [fieldErrors, setFieldErrors] = useState<Record<string, string | undefined>>({});
+  const [saved, setSaved] = useState(false);
+  const [isPending, startTransition] = useTransition();
+
+  const handleSave = () => {
+    setError(null);
+    setFieldErrors({});
+    setSaved(false);
+    startTransition(async () => {
+      const result = await updateCustomerProfileAction({ firstName, lastName, email, phone });
+      if (!result.success) {
+        setError(result.error ?? "Couldn't save your profile.");
+        if (result.fieldErrors) {
+          setFieldErrors(Object.fromEntries(Object.entries(result.fieldErrors).map(([key, value]) => [key, value?.[0]])));
+        }
+        return;
+      }
+      setSaved(true);
+      router.refresh();
+    });
+  };
+
+  return (
+    <div className="space-y-4">
+      <CustomerAvatarPicker value={image || null} onChange={(url) => setImage(url ?? "")} />
+      <div className="grid grid-cols-2 gap-4">
+        <Input
+          label="First Name"
+          value={firstName}
+          onChange={(e) => setFirstName(e.target.value)}
+          error={fieldErrors.firstName}
+        />
+        <Input label="Last Name" value={lastName} onChange={(e) => setLastName(e.target.value)} error={fieldErrors.lastName} />
+      </div>
+      <Input
+        label="Email Address"
+        type="email"
+        value={email}
+        onChange={(e) => setEmail(e.target.value)}
+        error={fieldErrors.email}
+      />
+      <Input
+        label="Phone Number"
+        type="tel"
+        placeholder="+44 7700 900000"
+        value={phone}
+        onChange={(e) => setPhone(e.target.value)}
+        error={fieldErrors.phone}
+      />
+      {error && (
+        <p role="alert" className="text-danger text-sm font-medium">
+          {error}
+        </p>
+      )}
+      {saved && !error && (
+        <p role="status" className="text-accent-foreground text-sm font-medium">
+          Saved.
+        </p>
+      )}
+      <Button className="w-full" isLoading={isPending} onClick={handleSave}>
+        Save
+      </Button>
+    </div>
+  );
+}
diff --git a/src/features/customer/components/preferred-barber-picker.tsx b/src/features/customer/components/preferred-barber-picker.tsx
new file mode 100644
index 0000000..9af839b
--- /dev/null
+++ b/src/features/customer/components/preferred-barber-picker.tsx
@@ -0,0 +1,92 @@
+"use client";
+
+import Image from "next/image";
+import { Check } from "lucide-react";
+import { useState, useTransition } from "react";
+import { updatePreferredBarberAction } from "@/features/customer/actions/profile";
+
+export interface PreferredBarberOption {
+  id: string;
+  name: string;
+  avatarUrl?: string;
+}
+
+/** Tap-to-select, saves immediately (no separate Save step) — same "pick one" pattern as the Reviews manager's hide/unhide toggle: one action per row, optimistic update, revert on failure. */
+export function PreferredBarberPicker({
+  staff,
+  initialPreferredId,
+}: {
+  staff: PreferredBarberOption[];
+  initialPreferredId: string | null;
+}) {
+  const [preferredId, setPreferredId] = useState(initialPreferredId);
+  const [pendingId, setPendingId] = useState<string | null>(null);
+  const [error, setError] = useState<string | null>(null);
+  const [, startTransition] = useTransition();
+
+  const select = (id: string | null) => {
+    if (id === preferredId) return;
+    const previous = preferredId;
+    setError(null);
+    setPreferredId(id);
+    setPendingId(id ?? "none");
+    startTransition(async () => {
+      const result = await updatePreferredBarberAction(id);
+      if (!result.success) {
+        setPreferredId(previous);
+        setError(result.error ?? "Couldn't save your preference.");
+      }
+      setPendingId(null);
+    });
+  };
+
+  return (
+    <div className="space-y-3">
+      {error && (
+        <p role="alert" className="text-danger text-sm font-medium">
+          {error}
+        </p>
+      )}
+      <ul className="divide-line divide-y rounded-md border border-line bg-white">
+        <li>
+          <button
+            type="button"
+            onClick={() => select(null)}
+            disabled={pendingId !== null}
+            className="hover:bg-stone flex w-full items-center gap-3 px-5 py-4 text-left text-sm font-bold disabled:opacity-60"
+          >
+            <div className="bg-stone flex h-11 w-11 shrink-0 items-center justify-center rounded-full text-muted">—</div>
+            <span className="flex-1">No preference</span>
+            {preferredId === null && <Check className="text-accent h-4 w-4" aria-hidden="true" />}
+          </button>
+        </li>
+        {staff.map((barber) => (
+          <li key={barber.id}>
+            <button
+              type="button"
+              onClick={() => select(barber.id)}
+              disabled={pendingId !== null}
+              className="hover:bg-stone flex w-full items-center gap-3 px-5 py-4 text-left text-sm font-bold disabled:opacity-60"
+            >
+              {barber.avatarUrl ? (
+                <Image
+                  src={barber.avatarUrl}
+                  alt=""
+                  width={44}
+                  height={44}
+                  className="h-11 w-11 shrink-0 rounded-full border border-line object-cover"
+                />
+              ) : (
+                <div className="bg-stone text-muted flex h-11 w-11 shrink-0 items-center justify-center rounded-full text-sm font-bold">
+                  {barber.name.charAt(0)}
+                </div>
+              )}
+              <span className="flex-1">{barber.name}</span>
+              {preferredId === barber.id && <Check className="text-accent h-4 w-4" aria-hidden="true" />}
+            </button>
+          </li>
+        ))}
+      </ul>
+    </div>
+  );
+}
diff --git a/src/features/customer/schemas.ts b/src/features/customer/schemas.ts
new file mode 100644
index 0000000..9828a1c
--- /dev/null
+++ b/src/features/customer/schemas.ts
@@ -0,0 +1,10 @@
+import { z } from "zod";
+
+/** Shared between the customer profile-edit form and its server action, same rationale as auth/schemas.ts. */
+export const customerProfileSchema = z.object({
+  firstName: z.string().trim().min(1, "First name is required"),
+  lastName: z.string().trim().min(1, "Last name is required"),
+  email: z.email("Enter a valid email address"),
+  phone: z.string().trim().optional().or(z.literal("")),
+});
+export type CustomerProfileInput = z.infer<typeof customerProfileSchema>;
diff --git a/src/services/customer/__tests__/customer.service.integration.test.ts b/src/services/customer/__tests__/customer.service.integration.test.ts
new file mode 100644
index 0000000..2f6fb08
--- /dev/null
+++ b/src/services/customer/__tests__/customer.service.integration.test.ts
@@ -0,0 +1,144 @@
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { setCustomerAvatar, updateCustomerProfile, updatePreferredBarber } from "@/services/customer/customer.service";
+import {
+  cleanupTestBusiness,
+  createTestBusiness,
+  createTestCustomer,
+  createTestStaff,
+  prisma,
+} from "@/services/scheduling/__tests__/fixtures";
+import type { TestBusiness } from "@/services/scheduling/__tests__/fixtures";
+
+describe("customer.service (integration)", () => {
+  let business: TestBusiness;
+
+  beforeEach(async () => {
+    business = await createTestBusiness();
+  });
+
+  afterEach(async () => {
+    await cleanupTestBusiness(business);
+  });
+
+  describe("updateCustomerProfile", () => {
+    it("updates both User and CustomerProfile", async () => {
+      const { userId } = await createTestCustomer(business);
+
+      // Distinct from the phone number, not just the email — User.phone has
+      // its own unique constraint, so a hardcoded literal here would
+      // collide with any other row (seed data, another test run) that
+      // happens to use the same number.
+      const phone = `+44 7700 ${Math.floor(100000 + Math.random() * 900000)}`;
+      const result = await updateCustomerProfile(prisma, {
+        userId,
+        firstName: "Jamie",
+        lastName: "Fraser",
+        email: `jamie-${userId}@test.local`,
+        phone,
+      });
+      expect(result.success).toBe(true);
+
+      const user = await prisma.user.findUniqueOrThrow({ where: { id: userId } });
+      expect(user.name).toBe("Jamie Fraser");
+      expect(user.email).toBe(`jamie-${userId}@test.local`);
+      expect(user.phone).toBe(phone);
+
+      const profile = await prisma.customerProfile.findUniqueOrThrow({ where: { userId } });
+      expect(profile.firstName).toBe("Jamie");
+      expect(profile.lastName).toBe("Fraser");
+      expect(profile.phone).toBe(phone);
+    });
+
+    it("creates a CustomerProfile via upsert for a user who has never booked", async () => {
+      const user = await prisma.user.create({ data: { email: `never-booked-${Date.now()}@test.local`, name: "New User" } });
+      business.createdUserIds.push(user.id);
+
+      const result = await updateCustomerProfile(prisma, {
+        userId: user.id,
+        firstName: "New",
+        lastName: "User",
+        email: user.email!,
+        phone: "",
+      });
+      expect(result.success).toBe(true);
+
+      const profile = await prisma.customerProfile.findUniqueOrThrow({ where: { userId: user.id } });
+      expect(profile.firstName).toBe("New");
+      expect(profile.isGuest).toBe(false);
+    });
+
+    it("rejects an email already used by another user", async () => {
+      const { userId } = await createTestCustomer(business);
+      const other = await createTestCustomer(business);
+      const otherUser = await prisma.user.findUniqueOrThrow({ where: { id: other.userId } });
+
+      const result = await updateCustomerProfile(prisma, {
+        userId,
+        firstName: "Jamie",
+        lastName: "Fraser",
+        email: otherUser.email!,
+        phone: "",
+      });
+      expect(result.success).toBe(false);
+      expect(result.field).toBe("email");
+    });
+  });
+
+  describe("setCustomerAvatar", () => {
+    it("sets User.image and returns the previous value", async () => {
+      const { userId } = await createTestCustomer(business);
+
+      const first = await setCustomerAvatar(prisma, { userId, url: "/api/media/customer-avatars/a.jpg" });
+      expect(first.previousUrl).toBeNull();
+      let user = await prisma.user.findUniqueOrThrow({ where: { id: userId } });
+      expect(user.image).toBe("/api/media/customer-avatars/a.jpg");
+
+      const second = await setCustomerAvatar(prisma, { userId, url: "/api/media/customer-avatars/b.jpg" });
+      expect(second.previousUrl).toBe("/api/media/customer-avatars/a.jpg");
+      user = await prisma.user.findUniqueOrThrow({ where: { id: userId } });
+      expect(user.image).toBe("/api/media/customer-avatars/b.jpg");
+
+      const cleared = await setCustomerAvatar(prisma, { userId, url: null });
+      expect(cleared.previousUrl).toBe("/api/media/customer-avatars/b.jpg");
+      user = await prisma.user.findUniqueOrThrow({ where: { id: userId } });
+      expect(user.image).toBeNull();
+    });
+  });
+
+  describe("updatePreferredBarber", () => {
+    it("sets and clears a preferred barber on an existing CustomerProfile", async () => {
+      const { userId } = await createTestCustomer(business);
+      const { staffId } = await createTestStaff(business);
+
+      const set = await updatePreferredBarber(prisma, { userId, staffId });
+      expect(set.success).toBe(true);
+      let profile = await prisma.customerProfile.findUniqueOrThrow({ where: { userId } });
+      expect(profile.preferredBarberId).toBe(staffId);
+
+      const cleared = await updatePreferredBarber(prisma, { userId, staffId: null });
+      expect(cleared.success).toBe(true);
+      profile = await prisma.customerProfile.findUniqueOrThrow({ where: { userId } });
+      expect(profile.preferredBarberId).toBeNull();
+    });
+
+    it("creates a CustomerProfile from session User data when none exists yet", async () => {
+      const user = await prisma.user.create({ data: { email: `no-profile-${Date.now()}@test.local`, name: "Casey Rivers" } });
+      business.createdUserIds.push(user.id);
+      const { staffId } = await createTestStaff(business);
+
+      const result = await updatePreferredBarber(prisma, { userId: user.id, staffId });
+      expect(result.success).toBe(true);
+
+      const profile = await prisma.customerProfile.findUniqueOrThrow({ where: { userId: user.id } });
+      expect(profile.firstName).toBe("Casey");
+      expect(profile.lastName).toBe("Rivers");
+      expect(profile.preferredBarberId).toBe(staffId);
+    });
+
+    it("rejects a staffId that doesn't exist", async () => {
+      const { userId } = await createTestCustomer(business);
+      const result = await updatePreferredBarber(prisma, { userId, staffId: "not-a-real-staff-id" });
+      expect(result.success).toBe(false);
+    });
+  });
+});
diff --git a/src/services/customer/customer.service.ts b/src/services/customer/customer.service.ts
index 7b6e213..46ca166 100644
--- a/src/services/customer/customer.service.ts
+++ b/src/services/customer/customer.service.ts
@@ -149,3 +149,120 @@ export function matchesCustomerSearch(
     (customer.phone ?? "").toLowerCase().includes(normalized)
   );
 }
+
+export interface UpdateCustomerProfileParams {
+  userId: string;
+  firstName: string;
+  lastName: string;
+  email: string;
+  phone: string;
+}
+
+export interface UpdateCustomerProfileResult {
+  success: boolean;
+  error?: string;
+  /** Set only for a validation failure the caller should surface on a specific field (currently just a taken email). */
+  field?: "email";
+}
+
+/**
+ * A signed-in customer editing their own name/email/phone — see
+ * features/customer/actions/profile.ts, the only caller. Writes both User
+ * (the actual auth/session record, same split staff profile editing uses
+ * in staff.service.ts's updateStaffProfile) and CustomerProfile (the
+ * denormalized firstName/lastName/email/phone copy read everywhere else —
+ * see this file's own header on why the two can drift). A customer who has
+ * never booked yet has no CustomerProfile row at all, so this upserts
+ * rather than assuming one exists. Photo is handled separately by
+ * setCustomerAvatar below — it uploads/deletes immediately rather than
+ * waiting for this form's Save.
+ */
+export async function updateCustomerProfile(
+  prisma: PrismaClient,
+  params: UpdateCustomerProfileParams,
+): Promise<UpdateCustomerProfileResult> {
+  const emailTaken = await prisma.user.findUnique({ where: { email: params.email }, select: { id: true } });
+  if (emailTaken && emailTaken.id !== params.userId) {
+    return { success: false, error: "That email is already in use.", field: "email" };
+  }
+
+  try {
+    await prisma.$transaction([
+      prisma.user.update({
+        where: { id: params.userId },
+        data: {
+          name: `${params.firstName} ${params.lastName}`.trim(),
+          email: params.email,
+          phone: params.phone || null,
+        },
+      }),
+      prisma.customerProfile.upsert({
+        where: { userId: params.userId },
+        create: {
+          userId: params.userId,
+          firstName: params.firstName,
+          lastName: params.lastName,
+          email: params.email,
+          phone: params.phone || null,
+          isGuest: false,
+        },
+        update: { firstName: params.firstName, lastName: params.lastName, email: params.email, phone: params.phone || null },
+      }),
+    ]);
+  } catch {
+    return { success: false, error: "Couldn't save your profile." };
+  }
+
+  return { success: true };
+}
+
+/**
+ * Directory customer avatar uploads are stored under — deliberately never
+ * inserted as a MediaAsset row (see features/customer/actions/profile.ts's
+ * uploadCustomerAvatarAction), so these files never show up in the staff/
+ * owner Media Manager library. Exported so the "is this old image one of
+ * ours to delete" check in that action uses the exact same value.
+ */
+export const CUSTOMER_AVATAR_CATEGORY = "customer-avatars";
+
+/** Swaps User.image, returning the previous value so the caller (uploadCustomerAvatarAction/removeCustomerAvatarAction) can delete the old file from disk after the DB write succeeds. */
+export async function setCustomerAvatar(
+  prisma: PrismaClient,
+  params: { userId: string; url: string | null },
+): Promise<{ previousUrl: string | null }> {
+  const previous = await prisma.user.findUniqueOrThrow({ where: { id: params.userId }, select: { image: true } });
+  await prisma.user.update({ where: { id: params.userId }, data: { image: params.url } });
+  return { previousUrl: previous.image };
+}
+
+/** Sets or clears (`staffId: null`) the customer's preferred barber — see Home's "Preferred Barber" display, the only other place this is read. */
+export async function updatePreferredBarber(
+  prisma: PrismaClient,
+  params: { userId: string; staffId: string | null },
+): Promise<{ success: boolean; error?: string }> {
+  if (params.staffId) {
+    const staff = await prisma.staffProfile.findUnique({ where: { id: params.staffId }, select: { id: true } });
+    if (!staff) return { success: false, error: "That barber couldn't be found." };
+  }
+
+  const existing = await prisma.customerProfile.findUnique({ where: { userId: params.userId } });
+  if (existing) {
+    await prisma.customerProfile.update({ where: { userId: params.userId }, data: { preferredBarberId: params.staffId } });
+    return { success: true };
+  }
+
+  const user = await prisma.user.findUniqueOrThrow({ where: { id: params.userId } });
+  const [firstName, ...rest] = (user.name ?? "").trim().split(/\s+/).filter(Boolean);
+  await prisma.customerProfile.create({
+    data: {
+      userId: params.userId,
+      firstName: firstName || "Customer",
+      lastName: rest.join(" "),
+      email: user.email ?? "",
+      phone: user.phone ?? undefined,
+      preferredBarberId: params.staffId,
+      isGuest: false,
+    },
+  });
+  return { success: true };
+}