diff --git a/API Server/README.md b/API Server/README.md
index ef73156..6353a6c 100644
--- a/API Server/README.md	
+++ b/API Server/README.md	
@@ -90,7 +90,7 @@ other users `read` or `write` access. Every car/service/part handler is gated by
 | `parts` | per-car parts catalog | car, name, part_number, category |
 | `car_shares` | grants another user access to a car | car, user, `permission` (read \| write) |
 | `organizations` | tenants | name (unique) |
-| `users` | login + profile (built-in auth collection) | name, email, avatar, `role` (user \| admin \| superadmin), `organization`, bio, theme, locale, date_format, font_size, deletion_requested_at |
+| `users` | login + profile (built-in auth collection) | name, email, avatar, `role` (user \| admin \| superadmin), `organization`, bio, theme, locale, date_format, currency, font_size, deletion_requested_at |
 
 **Spreadsheet formulas** (from the original `Car Service.xlsx`), reproduced by
 the API on read:
diff --git a/API Server/internal/api/me.go b/API Server/internal/api/me.go
index 8a0dbcd..afbb9d9 100644
--- a/API Server/internal/api/me.go	
+++ b/API Server/internal/api/me.go	
@@ -6,6 +6,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"regexp"
 	"strings"
 	"time"
 
@@ -28,6 +29,7 @@ type userRecord struct {
 	Theme               string `json:"theme"`
 	Locale              string `json:"locale"`
 	DateFormat          string `json:"date_format"`
+	Currency            string `json:"currency"`
 	FontSize            string `json:"font_size"`
 	DeletionRequestedAt string `json:"deletion_requested_at"`
 	Role                string `json:"role"`
@@ -45,6 +47,7 @@ func (rec userRecord) toModel() models.User {
 		Theme:      orDefault(rec.Theme, "system"),
 		Locale:     orDefault(rec.Locale, "en-US"),
 		DateFormat: orDefault(rec.DateFormat, "YMD"),
+		Currency:   orDefault(rec.Currency, "USD"),
 		FontSize:   orDefault(rec.FontSize, "medium"),
 		Role:       orDefault(rec.Role, "user"),
 		Created:    rec.Created,
@@ -90,6 +93,7 @@ type updateMeRequest struct {
 	Theme      *string `json:"theme"`
 	Locale     *string `json:"locale"`
 	DateFormat *string `json:"dateFormat"`
+	Currency   *string `json:"currency"`
 	FontSize   *string `json:"fontSize"`
 }
 
@@ -97,6 +101,23 @@ var validThemes = map[string]bool{"light": true, "dark": true, "system": true}
 var validDateFormats = map[string]bool{"YMD": true, "DMY_NUM": true, "DMY": true, "MDY": true}
 var validFontSizes = map[string]bool{"small": true, "medium": true, "large": true}
 
+// Kept in step with the users.currency select options in setup-pocketbase.mjs:
+// PocketBase rejects anything outside its own list, so accepting a wider set
+// here would only turn a clear 400 into a confusing upstream error.
+var validCurrencies = map[string]bool{
+	"EUR": true, "GBP": true, "CHF": true, "PLN": true, "CZK": true, "HUF": true,
+	"RON": true, "BGN": true, "DKK": true, "SEK": true, "NOK": true, "ISK": true,
+	"ALL": true, "AMD": true, "AZN": true, "BAM": true, "BYN": true, "GEL": true,
+	"MDL": true, "MKD": true, "RSD": true, "RUB": true, "TRY": true, "UAH": true,
+	"USD": true, "CAD": true, "AUD": true, "JPY": true,
+}
+
+// The clients pick language and region separately and join them into this tag,
+// so the stored value is only ever language-REGION. Enforcing that shape here
+// keeps a bad tag out of the record: the web app feeds the locale straight to
+// Intl, which throws on a malformed one rather than falling back.
+var localePattern = regexp.MustCompile(`^[a-z]{2}-[A-Z]{2}$`)
+
 // handleUpdateMe applies a partial update — only fields present in the request
 // body are touched, so the Account/Profile/Appearance sections of the settings
 // panel can each save independently without clobbering the others.
@@ -127,6 +148,10 @@ func (s *Server) handleUpdateMe(w http.ResponseWriter, r *http.Request) {
 		payload["theme"] = *in.Theme
 	}
 	if in.Locale != nil {
+		if !localePattern.MatchString(*in.Locale) {
+			writeError(w, http.StatusBadRequest, "locale must look like en-US")
+			return
+		}
 		payload["locale"] = *in.Locale
 	}
 	if in.DateFormat != nil {
@@ -136,6 +161,13 @@ func (s *Server) handleUpdateMe(w http.ResponseWriter, r *http.Request) {
 		}
 		payload["date_format"] = *in.DateFormat
 	}
+	if in.Currency != nil {
+		if !validCurrencies[*in.Currency] {
+			writeError(w, http.StatusBadRequest, "currency must be a supported ISO 4217 code")
+			return
+		}
+		payload["currency"] = *in.Currency
+	}
 	if in.FontSize != nil {
 		if !validFontSizes[*in.FontSize] {
 			writeError(w, http.StatusBadRequest, "fontSize must be small, medium, or large")
diff --git a/API Server/internal/models/models.go b/API Server/internal/models/models.go
index 660b605..0fd3cad 100644
--- a/API Server/internal/models/models.go	
+++ b/API Server/internal/models/models.go	
@@ -283,6 +283,7 @@ type User struct {
 	Theme      string `json:"theme"`      // light | dark | system
 	Locale     string `json:"locale"`     // e.g. "en-US"
 	DateFormat string `json:"dateFormat"` // YMD | DMY | MDY
+	Currency   string `json:"currency"`   // ISO 4217 code, e.g. "EUR"
 	FontSize   string `json:"fontSize"`   // small | medium | large
 	Role       string `json:"role"`       // user | admin
 
diff --git a/API Server/scripts/setup-pocketbase.mjs b/API Server/scripts/setup-pocketbase.mjs
index 14b7cf4..ba94367 100644
--- a/API Server/scripts/setup-pocketbase.mjs	
+++ b/API Server/scripts/setup-pocketbase.mjs	
@@ -361,6 +361,14 @@ const DESIRED = {
     F.select("theme", ["light", "dark", "system"]),
     F.text("locale"),
     F.select("date_format", ["YMD", "DMY_NUM", "DMY", "MDY"]),
+    // European currencies plus the non-European ones the panel already offered.
+    // Kept in step with validCurrencies in internal/api/me.go and CURRENCY_CODES
+    // in the web app's Settings.vue.
+    F.select("currency", [
+      "EUR", "GBP", "CHF", "PLN", "CZK", "HUF", "RON", "BGN", "DKK", "SEK", "NOK",
+      "ISK", "ALL", "AMD", "AZN", "BAM", "BYN", "GEL", "MDL", "MKD", "RSD", "RUB",
+      "TRY", "UAH", "USD", "CAD", "AUD", "JPY",
+    ]),
     F.select("font_size", ["small", "medium", "large"]),
     F.date("deletion_requested_at"),
     // Access role. Empty value is treated as "user" by the API.
diff --git a/Web App/web/src/lib/format.js b/Web App/web/src/lib/format.js
index dab58c0..a69ee71 100644
--- a/Web App/web/src/lib/format.js	
+++ b/Web App/web/src/lib/format.js	
@@ -28,9 +28,16 @@ export function formatDate(value) {
   }
 }
 
+// Every number we render goes through here so the grouping separator follows
+// the user's chosen region rather than the browser's own locale — otherwise the
+// odometer disagrees with the dates and costs beside it.
+function num(value) {
+  return Number(value).toLocaleString(prefs.locale || undefined);
+}
+
 export function formatKm(value) {
   if (value == null || value === "" || value === 0) return "—";
-  return Number(value).toLocaleString() + " km";
+  return num(value) + " km";
 }
 
 const DAY = 24 * 60 * 60 * 1000;
@@ -72,9 +79,9 @@ function dateSignal(nextServiceDate) {
 function kmSignal(currentKm, nextServiceKm) {
   if (!currentKm || !nextServiceKm) return { key: "unknown", label: "No km" };
   const remaining = nextServiceKm - currentKm;
-  if (remaining < 0) return { key: "overdue", label: `Service Overdue ${Math.abs(remaining).toLocaleString()} km` };
-  if (remaining <= KM_SOON) return { key: "soon", label: `In ${remaining.toLocaleString()} km` };
-  return { key: "ok", label: `${remaining.toLocaleString()} km left` };
+  if (remaining < 0) return { key: "overdue", label: `Service Overdue ${num(Math.abs(remaining))} km` };
+  if (remaining <= KM_SOON) return { key: "soon", label: `In ${num(remaining)} km` };
+  return { key: "ok", label: `${num(remaining)} km left` };
 }
 
 // serviceStatus combines the date- and km-based signals, returning the worse of
@@ -88,13 +95,17 @@ export function formatLiters(value) {
   return Number(value).toFixed(2) + " L";
 }
 
-// Amounts are unit-less on purpose: the project stores plain numbers and has no
-// currency setting, so imposing a symbol here would be a guess.
+// Amounts are stored as plain numbers; the user's currency setting only decides
+// how they are displayed. Nothing is converted — a figure entered as 40 reads as
+// 40 in whichever currency is selected.
 export function formatMoney(value) {
   if (value == null || value === "") return "—";
+  // No explicit fraction digits: currency style already pins them to the
+  // currency's minor unit, which keeps the 2 decimals the fuel figures were
+  // written for while still rendering yen without phantom sen.
   return Number(value).toLocaleString(prefs.locale || undefined, {
-    minimumFractionDigits: 2,
-    maximumFractionDigits: 2,
+    style: "currency",
+    currency: prefs.currency || "USD",
   });
 }
 
@@ -162,13 +173,13 @@ export function reminderStatus(rem) {
   else if (state === "overdue") {
     const parts = [];
     if (days != null && days < 0) parts.push(`${Math.abs(days)}d`);
-    if (km != null && km < 0) parts.push(`${Math.abs(km).toLocaleString()} km`);
+    if (km != null && km < 0) parts.push(`${num(Math.abs(km))} km`);
     label = parts.length ? `Overdue ${parts.join(" · ")}` : "Overdue";
   } else {
     // Lead with the trigger that is closest to firing.
     const parts = [];
     if (days != null && days >= 0) parts.push(days === 0 ? "today" : `${days}d`);
-    if (km != null && km >= 0) parts.push(`${km.toLocaleString()} km`);
+    if (km != null && km >= 0) parts.push(`${num(km)} km`);
     label = parts.length ? `Due in ${parts.join(" · ")}` : "Upcoming";
   }
   return { key: state, label, classes: REMINDER_STYLE[state] || REMINDER_STYLE.no_trigger };
diff --git a/Web App/web/src/prefs.js b/Web App/web/src/prefs.js
index 7370223..f7122e3 100644
--- a/Web App/web/src/prefs.js	
+++ b/Web App/web/src/prefs.js	
@@ -1,4 +1,4 @@
-// Appearance preferences (theme / locale / date format / font size), applied
+// Appearance preferences (theme / locale / date format / currency / font size), applied
 // to the document so every view — not just the Settings page — reflects them.
 import { reactive } from "vue";
 
@@ -6,6 +6,7 @@ export const prefs = reactive({
   theme: "system", // light | dark | system
   locale: "en-US",
   dateFormat: "YMD", // YMD | DMY | MDY
+  currency: "USD", // ISO 4217 code
   fontSize: "medium", // small | medium | large
 });
 
@@ -41,6 +42,7 @@ export function applyProfilePrefs(profile) {
   prefs.theme = profile.theme || "system";
   prefs.locale = profile.locale || "en-US";
   prefs.dateFormat = profile.dateFormat || "YMD";
+  prefs.currency = profile.currency || "USD";
   prefs.fontSize = profile.fontSize || "medium";
   applyTheme();
   applyFontSize();
diff --git a/Web App/web/src/views/CarDetail.vue b/Web App/web/src/views/CarDetail.vue
index 6ccc8bf..8676bf7 100644
--- a/Web App/web/src/views/CarDetail.vue	
+++ b/Web App/web/src/views/CarDetail.vue	
@@ -80,7 +80,7 @@ const dueReminders = computed(
 const TABS = [
   { key: "info", label: "Information" },
   { key: "services", label: "Service history" },
-  { key: "maintenance", label: "Maintenance log" },
+  { key: "maintenance", label: "Maintenance" },
   { key: "fuel", label: "Fuel" },
   { key: "documents", label: "Documents" },
   { key: "parts", label: "Parts catalog" },
@@ -538,11 +538,11 @@ onMounted(load);
         </div>
       </section>
 
-      <!-- Maintenance log -->
+      <!-- Maintenance -->
       <section v-else-if="activeTab === 'maintenance'">
         <div class="mb-3 flex items-center justify-between">
           <div>
-            <h2 class="text-lg font-bold tracking-[-0.02em] text-strong">Maintenance log</h2>
+            <h2 class="text-lg font-bold tracking-[-0.02em] text-strong">Maintenance</h2>
             <p class="text-sm text-muted">Workshop visits and repairs. Routine servicing lives under Service history.</p>
           </div>
           <button v-if="canWrite" class="dh-btn dh-btn-primary !px-3 !py-1.5" @click="openAddMaintenance">
diff --git a/Web App/web/src/views/Settings.vue b/Web App/web/src/views/Settings.vue
index d01d501..6d904d7 100644
--- a/Web App/web/src/views/Settings.vue	
+++ b/Web App/web/src/views/Settings.vue	
@@ -4,7 +4,7 @@ import { useRouter } from "vue-router";
 import { api } from "../api";
 import { state, logout, refreshProfile } from "../auth";
 import { prefs, applyProfilePrefs } from "../prefs";
-import { formatDate } from "../lib/format.js";
+import { formatDate, formatMoney } from "../lib/format.js";
 
 const router = useRouter();
 
@@ -133,6 +133,66 @@ async function saveAppearance(patch) {
 }
 
 const dateFormatExample = computed(() => formatDate(new Date().toISOString()));
+const currencyExample = computed(() => formatMoney(1234.5));
+
+// Language and region are two controls over the one stored BCP-47 locale, so
+// the pair can be mixed freely (English in Poland, say) rather than being
+// limited to the handful of combinations a single list could offer.
+//
+// Europe here means the sovereign states of the Council of Europe, plus Belarus,
+// Russia, Vatican City and Kosovo — geographically European but not members.
+// Dependencies (Gibraltar, Faroes, Åland) are left out: they are not countries,
+// and the languages/currencies they would add are already covered. US stays on
+// for the region list because it was there before this became a Europe list.
+const LANGUAGE_CODES = [
+  "sq", "hy", "az", "eu", "be", "bs", "bg", "ca", "hr", "cs", "da", "nl", "en",
+  "et", "fi", "fr", "gl", "ka", "de", "el", "hu", "is", "ga", "it", "lv", "lt",
+  "lb", "mk", "mt", "no", "pl", "pt", "ro", "rm", "ru", "sr", "sk", "sl", "es",
+  "sv", "tr", "uk", "cy",
+];
+const REGION_CODES = [
+  "AD", "AL", "AM", "AT", "AZ", "BA", "BE", "BG", "BY", "CH", "CY", "CZ", "DE",
+  "DK", "EE", "ES", "FI", "FR", "GB", "GE", "GR", "HR", "HU", "IE", "IS", "IT",
+  "LI", "LT", "LU", "LV", "MC", "MD", "ME", "MK", "MT", "NL", "NO", "PL", "PT",
+  "RO", "RS", "RU", "SE", "SI", "SK", "SM", "TR", "UA", "VA", "XK", "US",
+];
+// Mirrors validCurrencies in the API's me.go and the users.currency select in
+// setup-pocketbase.mjs — all three have to list the same codes.
+const CURRENCY_CODES = [
+  "EUR", "GBP", "CHF", "PLN", "CZK", "HUF", "RON", "BGN", "DKK", "SEK", "NOK",
+  "ISK", "ALL", "AMD", "AZN", "BAM", "BYN", "GEL", "MDL", "MKD", "RSD", "RUB",
+  "TRY", "UAH", "USD", "CAD", "AUD", "JPY",
+];
+
+// Labels come from Intl rather than a hand-kept translation table, so the lists
+// read in the user's own language ("Deutschland" once German is picked) and
+// sort by what is actually on screen. If a runtime cannot name a code it falls
+// back to the code itself, which is still selectable.
+function named(codes, type, withCode = false) {
+  let dn = null;
+  try {
+    dn = new Intl.DisplayNames([prefs.locale || "en-US"], { type });
+  } catch {
+    dn = null;
+  }
+  return codes
+    .map((code) => {
+      const name = dn?.of(code) || code;
+      return { code, label: withCode && name !== code ? `${name} (${code})` : name };
+    })
+    .sort((a, b) => a.label.localeCompare(b.label, prefs.locale || undefined));
+}
+
+const LANGUAGES = computed(() => named(LANGUAGE_CODES, "language"));
+const REGIONS = computed(() => named(REGION_CODES, "region"));
+const CURRENCIES = computed(() => named(CURRENCY_CODES, "currency", true));
+
+const language = computed(() => (prefs.locale || "en-US").split("-")[0]);
+const region = computed(() => (prefs.locale || "en-US").split("-")[1] || "US");
+
+function saveLocale({ lang = language.value, reg = region.value }) {
+  return saveAppearance({ locale: `${lang}-${reg}` });
+}
 
 // --- Profile: avatar + bio ---
 
@@ -438,15 +498,19 @@ onBeforeUnmount(() => {
 
         <div class="mb-5 grid gap-4 sm:grid-cols-2">
           <div>
-            <label class="dh-label">Language &amp; region</label>
-            <select :value="prefs.locale" class="dh-input" @change="saveAppearance({ locale: $event.target.value })">
-              <option value="en-US">English (US)</option>
-              <option value="en-GB">English (UK)</option>
-              <option value="pl-PL">Polski</option>
-              <option value="de-DE">Deutsch</option>
-              <option value="fr-FR">Français</option>
-              <option value="es-ES">Español</option>
+            <label class="dh-label">Language</label>
+            <select :value="language" class="dh-input" @change="saveLocale({ lang: $event.target.value })">
+              <option v-for="l in LANGUAGES" :key="l.code" :value="l.code">{{ l.label }}</option>
             </select>
+            <p class="mt-1 text-xs text-muted">Names of months and days.</p>
+          </div>
+
+          <div>
+            <label class="dh-label">Region</label>
+            <select :value="region" class="dh-input" @change="saveLocale({ reg: $event.target.value })">
+              <option v-for="r in REGIONS" :key="r.code" :value="r.code">{{ r.label }}</option>
+            </select>
+            <p class="mt-1 text-xs text-muted">Number and currency layout.</p>
           </div>
 
           <div>
@@ -459,6 +523,16 @@ onBeforeUnmount(() => {
             </select>
             <p class="mt-1 text-xs text-muted">Example: <span class="data">{{ dateFormatExample }}</span></p>
           </div>
+
+          <div>
+            <label class="dh-label">Currency</label>
+            <select :value="prefs.currency" class="dh-input" @change="saveAppearance({ currency: $event.target.value })">
+              <option v-for="c in CURRENCIES" :key="c.code" :value="c.code">{{ c.label }}</option>
+            </select>
+            <p class="mt-1 text-xs text-muted">
+              Example: <span class="data">{{ currencyExample }}</span> — display only, no amounts are converted.
+            </p>
+          </div>
         </div>
 
         <div>